diff --git a/crate/sync/Cargo.toml b/crate/sync/Cargo.toml
new file mode 100644
index 0000000..2b9fa6f
--- /dev/null
+++ b/crate/sync/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "ucore-sync"
+version = "0.1.0"
+authors = ["WangRunji <wangrunji0408@163.com>"]
+
+[dependencies]
diff --git a/crate/sync/src/main.rs b/crate/sync/src/main.rs
new file mode 100644
index 0000000..49c86fa
--- /dev/null
+++ b/crate/sync/src/main.rs
@@ -0,0 +1,7 @@
+mod mutex;
+mod monitor;
+
+fn main() {
+//    mutex::main();
+    monitor::main();
+}
\ No newline at end of file
diff --git a/crate/sync/src/monitor.rs b/crate/sync/src/monitor.rs
new file mode 100644
index 0000000..2c7cb8d
--- /dev/null
+++ b/crate/sync/src/monitor.rs
@@ -0,0 +1,82 @@
+use std::thread;
+use std::sync::{Mutex, Condvar, Arc};
+use std::time::Duration;
+
+struct Philosopher {
+    name: String,
+    left: usize,
+    right: usize,
+}
+
+impl Philosopher {
+    fn new(name: &str, left: usize, right: usize) -> Philosopher {
+        Philosopher {
+            name: name.to_string(),
+            left,
+            right,
+        }
+    }
+
+    fn eat(&self, table: &Table) {
+        {
+            let mut fork_status = table.fork_status.lock().unwrap();
+            if fork_status[self.left] {
+                fork_status = table.fork_condvar[self.left].wait(fork_status).unwrap()
+            }
+            fork_status[self.left] = true;
+            if fork_status[self.right] {
+                fork_status = table.fork_condvar[self.right].wait(fork_status).unwrap()
+            }
+            fork_status[self.right] = true;
+        }
+        println!("{} is eating.", self.name);
+        thread::sleep(Duration::from_secs(1));
+        {
+            let mut fork_status = table.fork_status.lock().unwrap();
+            fork_status[self.left] = false;
+            fork_status[self.right] = false;
+            table.fork_condvar[self.left].notify_one();
+            table.fork_condvar[self.right].notify_one();
+        }
+    }
+
+    fn think(&self) {
+        println!("{} is thinking.", self.name);
+        thread::sleep(Duration::from_secs(1));
+    }
+}
+
+struct Table {
+    fork_status: Mutex<Vec<bool>>,
+    fork_condvar: Vec<Condvar>,
+}
+
+pub fn main() {
+    let table = Arc::new(Table {
+        fork_status: Mutex::new(vec![false; 5]),
+        fork_condvar: vec![Condvar::new(), Condvar::new(), Condvar::new(), Condvar::new(), Condvar::new()],
+    });
+
+    let philosophers = vec![
+        Philosopher::new("1", 0, 1),
+        Philosopher::new("2", 1, 2),
+        Philosopher::new("3", 2, 3),
+        Philosopher::new("4", 3, 4),
+        Philosopher::new("5", 0, 4),
+    ];
+
+    let handles: Vec<_> = philosophers.into_iter().map(|p| {
+        let table = table.clone();
+
+        thread::spawn(move || {
+            for _ in 0..5 {
+                p.think();
+                p.eat(&table);
+            }
+        })
+    }).collect();
+
+    for h in handles {
+        h.join().unwrap();
+    }
+}
\ No newline at end of file
diff --git a/crate/sync/src/mutex.rs b/crate/sync/src/mutex.rs
new file mode 100644
index 0000000..06b3223
--- /dev/null
+++ b/crate/sync/src/mutex.rs
@@ -0,0 +1,71 @@
+use std::thread;
+use std::sync::{Mutex, Arc};
+use std::time::Duration;
+
+struct Philosopher {
+    name: String,
+    left: usize,
+    right: usize,
+}
+
+impl Philosopher {
+    fn new(name: &str, left: usize, right: usize) -> Philosopher {
+        Philosopher {
+            name: name.to_string(),
+            left,
+            right,
+        }
+    }
+
+    fn eat(&self, table: &Table) {
+        let _left = table.forks[self.left].lock().unwrap();
+        let _right = table.forks[self.right].lock().unwrap();
+
+        println!("{} is eating.", self.name);
+        thread::sleep(Duration::from_secs(1));
+    }
+
+    fn think(&self) {
+        println!("{} is thinking.", self.name);
+        thread::sleep(Duration::from_secs(1));
+    }
+}
+
+struct Table {
+    forks: Vec<Mutex<()>>,
+}
+
+pub fn main() {
+    let table = Arc::new(Table {
+        forks: vec![
+            Mutex::new(()),
+            Mutex::new(()),
+            Mutex::new(()),
+            Mutex::new(()),
+            Mutex::new(()),
+        ]
+    });
+
+    let philosophers = vec![
+        Philosopher::new("1", 0, 1),
+        Philosopher::new("2", 1, 2),
+        Philosopher::new("3", 2, 3),
+        Philosopher::new("4", 3, 4),
+        Philosopher::new("5", 0, 4),
+    ];
+
+    let handles: Vec<_> = philosophers.into_iter().map(|p| {
+        let table = table.clone();
+
+        thread::spawn(move || {
+            for _ in 0..5 {
+                p.think();
+                p.eat(&table);
+            }
+        })
+    }).collect();
+
+    for h in handles {
+        h.join().unwrap();
+    }
+}
\ No newline at end of file