diff --git a/docs/Grove_System.md b/docs/Grove_System.md
index 68109505..043356bd 100644
--- a/docs/Grove_System.md
+++ b/docs/Grove_System.md
@@ -177,6 +177,23 @@ The Grove I2C connector has the standard layout.   Pin 1 is the SCL signal and P
 |pin3   | VCC  | Power for Grove Module, 5V/3.3V|
 |pin4	| GND  | Ground |
 
+### Grove SPI
+
+The Grove SPI connector has the standard layout that uses two grove wires. For the first wire Pin 1 is the SCK signal and Pin 2 is the MISO signal. For the second wire Pin 1 is the MOSI signal and Pin 2 is the SS signal.  Power and Ground are the same as the other connectors.
+
+|pin|Function  | Note   |
+|--------|------|-----|
+|pin1	| SCK | Master Clock |
+|pin2   | MISO| Master in Slave out|
+|pin3   | VCC  | Power for Grove Module, 5V/3.3V|
+|pin4	| GND  | Ground |
+
+|pin|Function  | Note   |
+|--------|------|-----|
+|pin1	| MOSI | Master out Slave in |
+|pin2   | SS | Slave Select |
+|pin3   | VCC  | Power for Grove Module, 5V/3.3V|
+|pin4	| GND  | Ground |
 
 ## Grove Cables
 
@@ -359,4 +376,4 @@ Want some Grove modules for your project? Here are some recommend.
 |[More Details](http://www.seeedstudio.com/Grove-Line-Finder-p-825.html)|[More Details](http://www.seeedstudio.com/Grove-Ultrasonic-Ranger-p-960.html)|[More Details](http://www.seeedstudio.com/Grove-80cm-Infrared-Proximity-Sensor-p-788.html)|
 
 ## Tech Support
-Please submit any technical issue into our [forum](http://forum.seeedstudio.com/). <br /><p style="text-align:center"><a href="https://www.seeedstudio.com/act-4.html?utm_source=wiki&utm_medium=wikibanner&utm_campaign=newproducts" target="_blank"><img src="https://github.com/SeeedDocument/Wiki_Banner/raw/master/new_product.jpg" /></a></p>
\ No newline at end of file
+Please submit any technical issue into our [forum](http://forum.seeedstudio.com/). <br /><p style="text-align:center"><a href="https://www.seeedstudio.com/act-4.html?utm_source=wiki&utm_medium=wikibanner&utm_campaign=newproducts" target="_blank"><img src="https://github.com/SeeedDocument/Wiki_Banner/raw/master/new_product.jpg" /></a></p>