This paper proposes a design of CLC filter which is the output filter of a flyback type current source inverter (CSI) for a photovoltaic system. This applied inverting system is micro-inverter, so the capacity and size of the entire system is critical factor for system evaluation. The proposed CLC filter consists of a conventional CL filter and an additional capacitor. The CLC filter guarantees the same or better performance about the reduction of current ripple than that of the CL filter. In such a case, the CLC filter is composed of the capacitor and the inductor with smaller capacity than the components of the CL filter. It can help the applied micro-inverter to be smaller size and cost less. For the advanced stability of output CL filters, the effect of passive damping methods for the CL filter is analyzed according to the resistive damping’s location. Among these damping methods, the one which has low power consumption is applied to the CLC filter and the effect of this method is also analyzed. A simulation and experiment are conducted to verify the performance of the proposed CLC filter and the validity of passive damping method.