The purpose of this paper is to fabrication the Chip-On-Board LEDs solar simulator that can generate irradiance for the solar cell standard test condition and study the non- uniformity of the light source. Eighteen of fifty-watts of Chip-On-Board LEDs were applied to be the light source. The DC convertor circuit was developed to drive currents for them. The irradiance control was controlled via the USB data acquisition interface and LabVIEW program. The standard pyranometer was used for uniformity measurement. The uniformity test is based on the methods recommended in the IEC 60904-9 edition 2(2007). The results found that the non-uniformity of irradiance of this solar simulator is accordance with the IEC standard in class B. This LED solar simulator is easy to be used to control the irradiance flux and appropriate to be used to test the solar cell in the laboratory. Moreover, this idea can be applied to build the solar simulator for PV panel experimental set.