diff --git a/HeapSort.go b/HeapSort.go
index 8f848c6..0173ea8 100644
--- a/HeapSort.go
+++ b/HeapSort.go
@@ -1,9 +1,16 @@
 package sort
 
-import (
-	"reflect"
-)
+import "reflect"
 
+// HeapSort
+// This is a custom Heap Sort
+// You MUST define the compare function by yourself
+// compare function type: func(i,j interface{}) bool
+//
+// input: func([]interface{}, func(i,j interface{}) bool) []interface{}
+//
+// output slice and won't change the origin one
+// data = HeapSort(data, cmp), if you want to change origin slice
 func HeapSort(data interface{}, cmp func(i, j interface{}) bool) []interface{} {
 	value := reflect.ValueOf(data)
 	dataS := make([]interface{}, value.Len())
@@ -55,7 +62,12 @@ func maxHeap(data []interface{}, len int, cmp func(i, j interface{}) bool) {
 	return
 }
 
-// INT
+// HeapSortInt
+// Heap Sort in Int type, sorting from small to big
+//
+// Input slice func(Int[])
+//
+// No output, just change origin slice
 func HeapSortInt(dataS []int) {
 	heapifyInt(dataS, len(dataS)/2-1, len(dataS))
 	maxHeapInt(dataS, len(dataS))
@@ -101,7 +113,12 @@ func maxHeapInt(data []int, len int) {
 	return
 }
 
-// INT32
+// HeapSortInt32
+// Heap Sort in Int32 type, sorting from small to big
+//
+// Input slice func(Int32[])
+//
+// No output, just change origin slice
 func HeapSortInt32(dataS []int32) {
 	heapifyInt32(dataS, len(dataS)/2-1, len(dataS))
 	maxHeapInt32(dataS, len(dataS))
@@ -147,7 +164,12 @@ func maxHeapInt32(data []int32, len int) {
 	return
 }
 
-// INT64
+// HeapSortInt64
+// Heap Sort in Int64 type, sorting from small to big
+//
+// Input slice func(Int64[])
+//
+// No output, just change origin slice
 func HeapSortInt64(dataS []int64) {
 	heapifyInt64(dataS, len(dataS)/2-1, len(dataS))
 	maxHeapInt64(dataS, len(dataS))
@@ -193,7 +215,12 @@ func maxHeapInt64(data []int64, len int) {
 	return
 }
 
-// FLOAT32
+// HeapSortFloat32
+// Heap Sort in Float32 type, sorting from small to big
+//
+// Input slice func(Float32[])
+//
+// No output, just change origin slice
 func HeapSortFloat32(dataS []float32) {
 	heapifyFloat32(dataS, len(dataS)/2-1, len(dataS))
 	maxHeapFloat32(dataS, len(dataS))
@@ -239,7 +266,12 @@ func maxHeapFloat32(data []float32, len int) {
 	return
 }
 
-// FLOAT64
+// HeapSortFloat64
+// Heap Sort in Float64 type, sorting from small to big
+//
+// Input slice func(Float64[])
+//
+// No output, just change origin slice
 func HeapSortFloat64(dataS []float64) {
 	heapifyFloat64(dataS, len(dataS)/2-1, len(dataS))
 	maxHeapFloat64(dataS, len(dataS))
diff --git a/InsertionSort.go b/InsertionSort.go
new file mode 100644
index 0000000..f00c68a
--- /dev/null
+++ b/InsertionSort.go
@@ -0,0 +1,120 @@
+package sort
+
+import "reflect"
+
+// InsertionSort
+// This is a custom Insertion Sort
+// You MUST define the compare function by yourself
+// compare function type: func(i,j interface{}) bool
+//
+// input: func([]interface{}, func(i,j interface{}) bool) []interface{}
+//
+// output slice and won't change the origin one
+// data = InsertionSort(data, cmp), if you want to change origin slice
+func InsertionSort(data interface{}, cmp func(i, j interface{}) bool) []interface{} {
+	value := reflect.ValueOf(data)
+	dataS := make([]interface{}, value.Len())
+	len := value.Len()
+	for a := 0; a < len; a++ {
+		dataS[a] = value.Index(a).Interface()
+	}
+	for i := 1; i < len; i++ {
+		tmp := dataS[i]
+		j := i - 1
+		for ; j >= 0 && cmp(dataS[j], tmp); j-- {
+			dataS[j+1] = dataS[j]
+		}
+		dataS[j+1] = tmp
+	}
+	return dataS
+}
+
+// InsertionSortInt
+// Insertion Sort in Int type, sorting from small to big
+//
+// Input slice func([]int)
+//
+// No output, just change origin slice
+func InsertionSortInt(dataS []int) {
+	len := len(dataS)
+	for i := 1; i < len; i++ {
+		tmp := dataS[i]
+		j := i - 1
+		for ; j >= 0 && dataS[j] > tmp; j-- {
+			dataS[j+1] = dataS[j]
+		}
+		dataS[j+1] = tmp
+	}
+}
+
+// InsertionSortInt32
+// Insertion Sort in Int32 type, sorting from small to big
+//
+// Input slice func([]int32)
+//
+// No output, just change origin slice
+func InsertionSortInt32(dataS []int32) {
+	len := len(dataS)
+	for i := 1; i < len; i++ {
+		tmp := dataS[i]
+		j := i - 1
+		for ; j >= 0 && dataS[j] > tmp; j-- {
+			dataS[j+1] = dataS[j]
+		}
+		dataS[j+1] = tmp
+	}
+}
+
+// InsertionSortInt64
+// Insertion Sort in Int64 type, sorting from small to big
+//
+// Input slice func([]int64)
+//
+// No output, just change origin slice
+func InsertionSortInt64(dataS []int64) {
+	len := len(dataS)
+	for i := 1; i < len; i++ {
+		tmp := dataS[i]
+		j := i - 1
+		for ; j >= 0 && dataS[j] > tmp; j-- {
+			dataS[j+1] = dataS[j]
+		}
+		dataS[j+1] = tmp
+	}
+}
+
+// InsertionSortFloat32
+// Insertion Sort in Float32 type, sorting from small to big
+//
+// Input slice func([]float32)
+//
+// No output, just change origin slice
+func InsertionSortFloat32(dataS []float32) {
+	len := len(dataS)
+	for i := 1; i < len; i++ {
+		tmp := dataS[i]
+		j := i - 1
+		for ; j >= 0 && dataS[j] > tmp; j-- {
+			dataS[j+1] = dataS[j]
+		}
+		dataS[j+1] = tmp
+	}
+}
+
+// InsertionSortFloat64
+// Insertion Sort in Float64 type, sorting from small to big
+//
+// Input slice func([]float64)
+//
+// No output, just change origin slice
+func InsertionSortFloat64(dataS []float64) {
+	len := len(dataS)
+	for i := 1; i < len; i++ {
+		tmp := dataS[i]
+		j := i - 1
+		for ; j >= 0 && dataS[j] > tmp; j-- {
+			dataS[j+1] = dataS[j]
+		}
+		dataS[j+1] = tmp
+	}
+}
diff --git a/IntroSort.go b/IntroSort.go
new file mode 100644
index 0000000..24478dd
--- /dev/null
+++ b/IntroSort.go
@@ -0,0 +1 @@
+package sort
diff --git a/example_InsertionSortInt_test.go b/example_InsertionSortInt_test.go
new file mode 100644
index 0000000..bcc2b38
--- /dev/null
+++ b/example_InsertionSortInt_test.go
@@ -0,0 +1,18 @@
+package sort_test
+
+import (
+	"fmt"
+
+	"github.com/goSTL/sort"
+)
+
+func ExampleInsertionSortInt() {
+	sample := []int{3, 138, 1, 674, 213, 23, 5, 2}
+	fmt.Println(sample)
+
+	sort.InsertionSortInt(sample)
+	fmt.Println(sample)
+	//Output:
+	//[3 138 1 674 213 23 5 2]
+	//[1 2 3 5 23 138 213 674]
+}
diff --git a/example_InsertionSort_test.go b/example_InsertionSort_test.go
new file mode 100644
index 0000000..bb5488e
--- /dev/null
+++ b/example_InsertionSort_test.go
@@ -0,0 +1,21 @@
+package sort_test
+
+import (
+	"fmt"
+
+	"github.com/goSTL/sort"
+)
+
+func ExampleInsertionSort() {
+	stu := []student{{5, "sam"}, {3, "lily"}, {7, "jacky"}, {1, "willy"}, {2, "steve"}, {3, "kally"}, {1, "gay"}, {-1, "10"}}
+	fmt.Println("original: \t", stu)
+
+	out := sort.InsertionSort(stu, cmp)
+	fmt.Println("[]interface{}: \t", out)
+
+	stu2 := make([]student, len(out))
+	for a := 0; a < len(out); a++ {
+		stu2[a] = out[a].(student)
+	}
+	fmt.Println("[]student: \t", stu2)
+}