diff --git a/ants.go b/ants.go
index 8096d06..81ccfa0 100644
--- a/ants.go
+++ b/ants.go
@@ -22,32 +22,42 @@ package ants
 import "github.com/iris-contrib/errors"
 
 const (
-	DEFAULT_POOL_SIZE           = 50000
+	// Default capacity for a default goroutine pool
+	DEFAULT_POOL_SIZE = 50000
+
+	// Interval time to clean up goroutines
 	DEFAULT_CLEAN_INTERVAL_TIME = 30
 )
 
+// Init a instance pool when importing ants
 var defaultPool, _ = NewPool(DEFAULT_POOL_SIZE)
 
+// Push submit a task to pool
 func Push(task f) error {
 	return defaultPool.Push(task)
 }
 
+// Running returns the number of the currently running goroutines
 func Running() int {
 	return defaultPool.Running()
 }
 
+// Cap returns the capacity of this default pool
 func Cap() int {
 	return defaultPool.Cap()
 }
 
+// Free returns the available goroutines to work
 func Free() int {
 	return defaultPool.Free()
 }
 
+// Release Closed the default pool
 func Release() {
-
+	defaultPool.Release()
 }
 
+// Errors for the Ants API
 var (
 	PoolSizeInvalidError = errors.New("invalid size for pool")
 	PoolClosedError      = errors.New("this pool has been closed")
diff --git a/ants_test.go b/ants_test.go
index 5a1b696..3ee3da4 100644
--- a/ants_test.go
+++ b/ants_test.go
@@ -26,9 +26,7 @@ var n = 1000000
 //}
 
 func forSleep() {
-	time.Sleep(time.Millisecond)
-	//for i := 0; i < 10000; i++ {
-	//}
+	time.Sleep(3 * time.Millisecond)
 }
 
 func TestNoPool(t *testing.T) {
diff --git a/pool.go b/pool.go
index eedbd23..473e7ca 100644
--- a/pool.go
+++ b/pool.go
@@ -29,14 +29,30 @@ type sig struct{}
 
 type f func()
 
+// Pool accept the tasks from client,it will limit the total
+// of goroutines to a given number by recycling goroutines.
 type Pool struct {
+	// Capacity of the pool.
 	capacity   int32
+
+	// The number of the currently running goroutines.
 	running    int32
+
+	// Signal is used to notice pool there are available
+	// workers which can be sent to work.
 	freeSignal chan sig
+
+	// A slice that store the available workers.
 	workers    []*Worker
+
 	workerPool sync.Pool
+
+	// It is used to notice the pool to closed itself.
 	release    chan sig
+
 	lock       sync.Mutex
+
+	// It is used to confirm whether this pool has been closed.
 	closed     int32
 }
 
@@ -56,6 +72,8 @@ func NewPool(size int) (*Pool, error) {
 
 //-------------------------------------------------------------------------
 
+// scanAndClean is a goroutine who will periodically clean up
+// after it is noticed that this pool is closed.
 func (p *Pool) scanAndClean() {
 	ticker := time.NewTicker(DEFAULT_CLEAN_INTERVAL_TIME * time.Second)
 	go func() {
@@ -72,6 +90,7 @@ func (p *Pool) scanAndClean() {
 	}()
 }
 
+// Push submit a task to pool
 func (p *Pool) Push(task f) error {
 	if atomic.LoadInt32(&p.closed) == 1 {
 		return PoolClosedError
@@ -81,18 +100,22 @@ func (p *Pool) Push(task f) error {
 	return nil
 }
 
+// Running returns the number of the currently running goroutines
 func (p *Pool) Running() int {
 	return int(atomic.LoadInt32(&p.running))
 }
 
+// Free returns the available goroutines to work
 func (p *Pool) Free() int {
 	return int(atomic.LoadInt32(&p.capacity) - atomic.LoadInt32(&p.running))
 }
 
+// Cap returns the capacity of this pool
 func (p *Pool) Cap() int {
 	return int(atomic.LoadInt32(&p.capacity))
 }
 
+// Release Closed this pool
 func (p *Pool) Release() error {
 	p.lock.Lock()
 	atomic.StoreInt32(&p.closed, 1)
@@ -101,12 +124,14 @@ func (p *Pool) Release() error {
 	return nil
 }
 
+// Resize change the capacity of this pool
 func (p *Pool) ReSize(size int) {
 	atomic.StoreInt32(&p.capacity, int32(size))
 }
 
 //-------------------------------------------------------------------------
 
+// getWorker returns a available worker to run the tasks.
 func (p *Pool) getWorker() *Worker {
 	var w *Worker
 	waiting := false
@@ -157,6 +182,7 @@ func (p *Pool) getWorker() *Worker {
 	return w
 }
 
+// putWorker puts a worker back into free pool, recycling the goroutines.
 func (p *Pool) putWorker(worker *Worker) {
 	p.workerPool.Put(worker)
 	p.lock.Lock()
diff --git a/worker.go b/worker.go
index 5acc864..2d9478a 100644
--- a/worker.go
+++ b/worker.go
@@ -24,11 +24,19 @@ import (
 	"sync/atomic"
 )
 
+// Worker is the actual executor who run the tasks,
+// it will start a goroutine that accept tasks and
+// perform function calls.
 type Worker struct {
+	// A pool who owns this worker.
 	pool *Pool
+
+	// The job should be done.
 	task chan f
 }
 
+// run will start a goroutine to repeat the process
+// that perform the function calls.
 func (w *Worker) run() {
 	go func() {
 		for f := range w.task {
@@ -42,10 +50,12 @@ func (w *Worker) run() {
 	}()
 }
 
+// stop this worker.
 func (w *Worker) stop() {
 	w.task <- nil
 }
 
+// sendTask send a task to this worker.
 func (w *Worker) sendTask(task f) {
 	w.task <- task
 }