This paper proposes a control method that is suitable to the structure of multiple boost type's power factor correctors in a series connection. The proposed control idea is based on one-cycle control, which has the advantage of obtaining the unity power factor function without detecting the input source voltage, thus resulting in a simple control circuit. This research also focuses on the compensation scheme used in the unbalanced loads conditions, and a prototype of two serial power factor correctors' system with 500 W rating for each module is set to verify the control idea.