Solar power is widely used in many industries and focus on studying on how to make a solar electrical power with the higher transfer efficiency and higher operating stability. There are various types of solar cell defects in fabrication and operation. Various defects of solar cell might lower the photoelectron transformation efficiency. Among these defects, micro cracks occurring in the interior of solar wafers are most crucial. Micro cracks of solar cell is difficult to detect or visible in normal light. Currently, the most common method to detect invisible micro crack in solar cell is used by electroluminescence (EL) technique. In this study, based on crystalline silicon solar cells we investigate electro characteristics such as open voltage (Voc) and short-circuit current (Isc) after EL test of cell. In addition, we also develop an EL image inspection system for roughly evaluation in normal area of the solar cell under test. However, this is an experimental prototyping system, the accuracy of micro cracks detection for solar cell is still depended on the quality of EL image and test instruments settings.