The microchip fabricated by MEMS technology is successfully used to finish the electrophoresis process. A novel electrophoresis analysis protocol of the trace enzyme of lactate dehydrogenase(LDH) on microfluidic chip platform is developed with a Xe lamp-induced fluorescence detection system. Satisfactory separation of LDH was achieved in 75 mmol/L borate buffer containing 9.73 μmol/L calcium lactate as running buffer (pH 9.4) within 4 min. The detection of LDH limits (S/N=3) is 6×10^-3 U/L. The coefficients of variation of peak time and areas were 5.32% and 3.17%. The method is easily operated. To application microfluidic chips with the method, the sensitive of detectable enzyme will be much more improved．The method for trace enzymes has potential for clinical application.