diff --git a/gomore/04_fan_in/fan_in_out_test.go b/gomore/04_fan_in/fan_in_out_test.go
new file mode 100644
index 0000000..c687d06
--- /dev/null
+++ b/gomore/04_fan_in/fan_in_out_test.go
@@ -0,0 +1,31 @@
+package fanin
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestFanInOutNumbersSeq(T *testing.T) {
+
+	//一路输入源
+	dataStreams := []int{13, 44, 56, 99, 9, 45, 67, 90, 78, 23}
+	// generate the common channel with inputs
+	inputChan1 := generateNumbersPipeline(dataStreams)
+	inputChan2 := generateNumbersPipeline(dataStreams)
+
+	//this is a fanout operation
+	// Fan-out to 2 Go-routine
+	c1 := squareNumber(inputChan1)
+	c2 := squareNumber(inputChan2)
+
+	//fanIn data for the squared numbers
+	out := Merge(c1, c2)
+
+	sum := 0
+
+	for c := range out {
+		sum += c
+	}
+
+	fmt.Printf("Total Sum of Squares by FanIn : %d\n", sum)
+}