In this paper, a method of improving the input current total harmonics distortion (THD) as well as power factor of three phase diode rectifier is implemented. In this method, a single-switch diode bridge boost-type rectifier in parallel with a pulse width modulation (PWM) three-phase unidirectional boost rectifier are used across the three-phase supply and load. The objective is to obtain a structure capable of providing sinusoidal input currents with low harmonic distortion and dc output voltage regulation. The operation of the converter is fully analyzed and simulation is also presented in this paper.