diff --git a/src/config.rs b/src/config.rs
index 4e19032..0ddb4f1 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -6,11 +6,9 @@ use std::sync::atomic::{AtomicUsize, Ordering};
 // default stack size, in usize
 // windows has a minimal size as 0x4a8!!!!
 const DEFAULT_STACK_SIZE: usize = 6 * 1024 * 1024;
-const DEFAULT_POOL_CAPACITY: usize = 100;
 
 static WORKERS: AtomicUsize = AtomicUsize::new(0);
 static STACK_SIZE: AtomicUsize = AtomicUsize::new(DEFAULT_STACK_SIZE);
-static POOL_CAPACITY: AtomicUsize = AtomicUsize::new(DEFAULT_POOL_CAPACITY);
 
 /// `mco` Configuration type
 pub struct Config;
@@ -46,25 +44,6 @@ impl Config {
         }
     }
 
-    /// set cached coroutine pool number
-    ///
-    /// if you pass 0 to it, will use internal default
-    pub fn set_pool_capacity(&self, capacity: usize) -> &Self {
-        info!("set pool capacity={:?}", capacity);
-        POOL_CAPACITY.store(capacity, Ordering::Release);
-        self
-    }
-
-    /// get the coroutine pool capacity
-    pub fn get_pool_capacity(&self) -> usize {
-        let size = POOL_CAPACITY.load(Ordering::Acquire);
-        if size != 0 {
-            size
-        } else {
-            DEFAULT_POOL_CAPACITY
-        }
-    }
-
     /// set default coroutine stack size in usize
     ///
     /// if you pass 0 to it, will use internal default
diff --git a/src/coroutine_impl.rs b/src/coroutine_impl.rs
index 6592428..1ed5b80 100644
--- a/src/coroutine_impl.rs
+++ b/src/coroutine_impl.rs
@@ -78,10 +78,6 @@ impl Done {
                 name, size, used
             );
         }
-
-        if size == config().get_stack_size() {
-            get_scheduler().pool.put(co);
-        }
     }
 }
 
@@ -296,15 +292,7 @@ impl Builder {
     {
         static DONE: Done = Done {};
 
-        let sched = get_scheduler();
         let stack_size = self.stack_size.unwrap_or_else(|| config().get_stack_size());
-        let _co = if stack_size == config().get_stack_size() {
-            let co = sched.pool.get();
-            co.prefetch();
-            Some(co)
-        } else {
-            None
-        };
 
         // create a join resource, shared by waited coroutine and *this* coroutine
         let panic = Arc::new(AtomicCell::new(None));
@@ -330,15 +318,9 @@ impl Builder {
             subscriber
         };
 
-        let mut co = if let Some(mut c) = _co {
-            // re-init the closure
-            c.init_code(closure);
-            c
-        } else {
-            CoroutineImpl {
-                worker_thread_id: None,
-                inner: Gn::new_opt(stack_size, closure),
-            }
+        let mut co =   CoroutineImpl {
+            worker_thread_id: None,
+            inner: Gn::new_opt(stack_size, closure),
         };
 
         let handle = Coroutine::new(self.name, stack_size);
diff --git a/src/pool.rs b/src/pool.rs
index b3b9778..b2b828a 100644
--- a/src/pool.rs
+++ b/src/pool.rs
@@ -21,7 +21,7 @@ impl CoroutinePool {
     }
 
     pub fn new() -> Self {
-        let capacity = config().get_pool_capacity();
+        let capacity = 100;
         let pool = Queue::new(capacity);
         for _ in 0..capacity {
             let co = Self::create_dummy_coroutine();
diff --git a/src/scheduler.rs b/src/scheduler.rs
index a2b6c79..62e5dd9 100644
--- a/src/scheduler.rs
+++ b/src/scheduler.rs
@@ -7,7 +7,6 @@ use std::time::Duration;
 use crate::config::config;
 use crate::coroutine_impl::{run_coroutine, CoroutineImpl};
 use crate::io::{EventLoop, Selector};
-use crate::pool::CoroutinePool;
 use crate::std::sync::AtomicOption;
 use crate::timeout_list;
 use crate::yield_now::set_co_para;
@@ -183,7 +182,6 @@ fn steal_local<T>(stealer: &deque::Stealer<T>, local: &deque::Worker<T>) -> Opti
 
 #[repr(align(128))]
 pub struct Scheduler {
-    pub pool: CoroutinePool,
     event_loop: EventLoop,
     global_queue: dark_std::sync::SyncVec<CoroutineImpl>,
     local_queues: Vec<deque::Worker<CoroutineImpl>>,
@@ -210,7 +208,6 @@ impl Scheduler {
             stealers.push(stealers_l);
         }
         Box::new(Scheduler {
-            pool: CoroutinePool::new(),
             event_loop: EventLoop::new(workers).expect("can't create event_loop"),
             global_queue: dark_std::sync::SyncVec::new(),
             local_queues,