This text introduce a sort of new soft switching Boost converter. The conventional Boost converter generates switching loss at turn on and off. So the whole system's efficiency is reduced. The proposed converter utiLizes soft switching method using an auxiLiary switch and resonant cirCuit. Therefore, the converter reduces switching loss lower than the hard switching. The proposed soft switching Boost converter can be appLied to photovoltaic system, power factor correction and so forth. The operation principles of the converter and the conditions for reaLization of soft switching are analyzed in detail, simulation analysis is given by the MATLAB/SimuLink. It s simulation results prove that all the switChes in soft switching state and the efficiency of the converter is improved.