Gamma correction is used to correct the nonlinear relationship between luminance and brightness, to vision information of reproduction source objects truly. So the principle of Gamma correction in Organic Light Emitting Diode (OLED) is described. For the gray scale distortion of the SVGA050 micro-display which is caused by the difference between the optical and electrical characteristic property, a Look-Up Table (LUT) Gamma correction system of AM-OLED is proposed, which is used the PIC18LF2550 as the MCU and the master of the I2C serial bus. The development of the hardware system measurement verifies the correction of VGA and CVBS video input and the picture quality also apparently improved.