This project addresses the challenges in on-line monitoring system for IGBT modules using lead frame for power electronic converter applications. IGBT modules are known as the weakest parts in power electronics system. The module using Lead frame instead of wire bonding has a high capability of power cycling. The purpose of this research is to develop on-line monitoring system for IGBT module using lead frame. When the lead frame module is used, the valiance due to degradation is smaller as compared with the case using the wire bond module. So high accuracy of monitoring system is required. First the accuracy of monitoring system required is designed. Then the measurement circuits is proposed to satisfy with the specification of this system. Finally, a single phase inverter controlled with PWM method is set up to validate it.