In this paper, a novel duty phase control (DPC) for single-phase boost-type switching-mode-rectifier (SMR) is developed and implemented in DSP-based system. Compared to the conventional multi-loop control structure with inner current loop and outer voltage loop, noted that there is only one voltage loop tuning the phase of pre-defined duty pattern (i.e. duty phase) in the proposed DPC. Due to no current loop, inductor current sampling and tracking control are unnecessary when SMRs are operated to obtain sinusoidal current waveform and regulate the output voltage. It implies that the single-loop DPC is simple, current sensorless and loopless, and is very adaptable to the implementation with digital and analog integrated circuits. In this paper, first, the effect of the duty phase on the input current is analyzed and modeled. It shows that the sinusoidal current waveform can be naturally generated by the pre-defined duty pattern and the current amplitude is roughly proportional to the controllable duty phase. Then, a voltage controller is designed to regulate the dc output voltage by tuning this duty phase. Finally, some simulated and experimental results have been given to illustrate the performances of the proposed DPC.