diff --git a/Cargo.lock b/Cargo.lock
index 285b107..65e2074 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,6 +2,132 @@
 # It is not intended for manual editing.
 version = 4
 
+[[package]]
+name = "cfg-if"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9555578bc9e57714c812a1f84e4fc5b4d21fcb063490c624de019f7464c91268"
+
+[[package]]
+name = "getrandom"
+version = "0.2.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "335ff9f135e4384c8150d6f27c6daed433577f86b4750418338c01a1a2528592"
+dependencies = [
+ "cfg-if",
+ "libc",
+ "wasi",
+]
+
+[[package]]
+name = "libc"
+version = "0.2.174"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1171693293099992e19cddea4e8b849964e9846f4acee11b3948bcc337be8776"
+
+[[package]]
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+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "85eae3c4ed2f50dcfe72643da4befc30deadb458a9b590d720cde2f2b1e97da9"
+dependencies = [
+ "zerocopy",
+]
+
+[[package]]
+name = "proc-macro2"
+version = "1.0.95"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "02b3e5e68a3a1a02aad3ec490a98007cbc13c37cbe84a3cd7b8e406d76e7f778"
+dependencies = [
+ "unicode-ident",
+]
+
+[[package]]
+name = "quote"
+version = "1.0.40"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1885c039570dc00dcb4ff087a89e185fd56bae234ddc7f056a945bf36467248d"
+dependencies = [
+ "proc-macro2",
+]
+
+[[package]]
+name = "rand"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "34af8d1a0e25924bc5b7c43c079c942339d8f0a8b57c39049bef581b46327404"
+dependencies = [
+ "libc",
+ "rand_chacha",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_chacha"
+version = "0.3.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e6c10a63a0fa32252be49d21e7709d4d4baf8d231c2dbce1eaa8141b9b127d88"
+dependencies = [
+ "ppv-lite86",
+ "rand_core",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ec0be4795e2f6a28069bec0b5ff3e2ac9bafc99e6a9a7dc3547996c5c816922c"
+dependencies = [
+ "getrandom",
+]
+
 [[package]]
 name = "ray-trace-w1"
 version = "0.1.0"
+dependencies = [
+ "rand",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.104"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "17b6f705963418cdb9927482fa304bc562ece2fdd4f616084c50b7023b435a40"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "unicode-ident"
+version = "1.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5a5f39404a5da50712a4c1eecf25e90dd62b613502b7e925fd4e4d19b5c96512"
+
+[[package]]
+name = "wasi"
+version = "0.11.1+wasi-snapshot-preview1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ccf3ec651a847eb01de73ccad15eb7d99f80485de043efb2f370cd654f4ea44b"
+
+[[package]]
+name = "zerocopy"
+version = "0.8.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1039dd0d3c310cf05de012d8a39ff557cb0d23087fd44cad61df08fc31907a2f"
+dependencies = [
+ "zerocopy-derive",
+]
+
+[[package]]
+name = "zerocopy-derive"
+version = "0.8.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9ecf5b4cc5364572d7f4c329661bcc82724222973f2cab6f050a4e5c22f75181"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
diff --git a/Cargo.toml b/Cargo.toml
index 8ab0327..29ab145 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,3 +4,4 @@ version = "0.1.0"
 edition = "2024"
 
 [dependencies]
+rand = "0.8.5"  # 使用最新稳定版
\ No newline at end of file
diff --git a/src/camera.rs b/src/camera.rs
index f54d38e..904d12c 100644
--- a/src/camera.rs
+++ b/src/camera.rs
@@ -1,5 +1,8 @@
 use crate::hittable::HittableList;
+use crate::math_utils::clamp;
 use crate::types_defined::{Camera, Color, Point, Ray, Vec3};
+use rand::rngs::ThreadRng;
+use rand::{Rng, thread_rng};
 
 impl Camera {
     pub fn new(
@@ -8,6 +11,7 @@ impl Camera {
         viewport_height: f32,
         camera_center: Point,
         focal_length: Vec3,
+        sample_times: i8,
     ) -> Self {
         let image_height = ((image_width as f32 / aspect_ratio) as i32).max(1);
         let viewport_width = viewport_height * (image_width as f32 / image_height as f32);
@@ -41,6 +45,7 @@ impl Camera {
             viewport_u_delta,
             viewport_v_delta,
             viewport_top_left_pixel_center,
+            sample_times: sample_times,
         }
     }
 
@@ -53,18 +58,30 @@ impl Camera {
             }
 
             for i in 0..self.image_width {
-                // every pixcel's position
-                let pixel_center = self.viewport_top_left_pixel_center
-                    + (i as f32 * self.viewport_u_delta)
-                    + (j as f32 * self.viewport_v_delta);
-                // Vector(camera, pixcel)
-                let ray_direction = pixel_center - self.camera_center;
-                // ray
-                let r = Ray::new(self.camera_center, ray_direction);
-                // determind color
-                let color = self.ray_color(&r, world);
+                // color
+                let mut color = Color::new(0.0, 0.0, 0.0);
+                let rng = &mut thread_rng();
+                for s in 0..self.sample_times {
+                    let bias = self.random_square(rng);
+                    let pix_sample = self.viewport_top_left_pixel_center
+                        + (i as f32 + bias.x) * self.viewport_u_delta
+                        + (j as f32 + bias.y) * self.viewport_v_delta;
+                    let r = Ray::new(self.camera_center, pix_sample - self.camera_center);
+                    let sample_color = self.ray_color(&r, world);
+                    color = color + sample_color;
+                }
+                // color * each sample color
+                color = color * (1.0 / self.sample_times as f32);
+
+                // clamp color rgb
+                let color_clamped = Color::new(
+                    clamp(color.x, 0.0, 1.0),
+                    clamp(color.y, 0.0, 1.0),
+                    clamp(color.z, 0.0, 1.0),
+                );
+
                 // content
-                img_content.push_str(color.to_color().as_str());
+                img_content.push_str(color_clamped.to_color().as_str());
                 img_content.push('\n');
             }
         }
@@ -88,4 +105,9 @@ impl Camera {
         // return background color.
         (1.0 - a) * Color::new(1.0, 1.0, 1.0) + a * Color::new(0.5, 0.7, 1.0)
     }
+
+    // -> [x, y, 0]
+    fn random_square(&self, rng: &mut ThreadRng) -> Vec3 {
+        Vec3::new(rng.gen_range(-0.5..0.1), rng.gen_range(-0.5..0.1), 0.0)
+    }
 }
diff --git a/src/main.rs b/src/main.rs
index f319a14..9451879 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -9,6 +9,7 @@ mod sphere;
 mod types_defined;
 mod vec3;
 mod write_file_util;
+mod math_utils;
 
 fn main() {
     camera_render();
@@ -16,11 +17,12 @@ fn main() {
 
 fn camera_render() {
     let camera = Camera::new(
-        800,
+        400,
         16.0 / 9.0,
         2.0,
         Point::new(0.0, 0.0, 0.0),
         Vec3::new(0.0, 0.0, -1.0),
+        10
     );
     // world
     // world objects(spheres)
diff --git a/src/math_utils.rs b/src/math_utils.rs
new file mode 100644
index 0000000..56a60cf
--- /dev/null
+++ b/src/math_utils.rs
@@ -0,0 +1,10 @@
+
+pub fn clamp(value: f32, low: f32, high: f32) -> f32 {
+    if value < low {
+        return low;
+    }
+    if value > high {
+        return high;
+    }
+    return value;
+}
\ No newline at end of file
diff --git a/src/types_defined.rs b/src/types_defined.rs
index a4ee75b..4b5a4c6 100644
--- a/src/types_defined.rs
+++ b/src/types_defined.rs
@@ -41,6 +41,9 @@ pub struct Camera {
     pub viewport_u_delta: Vec3,
     pub viewport_v_delta: Vec3,
     pub viewport_top_left_pixel_center: Vec3,
+
+    // sample times
+    pub sample_times: i8
 }
 
 /*