When the interleaved boost PFC converter operates in a light load (<15% of nominal load), the phase shedding control is commonly used to increase the converter efficiency. If the inductors are coupled for high power density applications, due to the strong mutual effects of the coupled inductor, the switching of the operation phase may lead to a current flowing in the non-operation phase. In this project, a two phase interleaved boost PFC converter with a coupled inductor in the single phase operation was analyzed. The operation modes of the converter in a switching cycle and a half line cycle were proposed, and the modes variation with the load changes, as well as the power distribution, was provided. A 1 kW prototype was built to verify the analysis, and it shown that the non-operation phase also delivers some power, which may worsen the converter efficiency and distort the average input current waveform. 1