This paper presents an algorithm to estimate the parameters of two closely spaced sinusoid signals. Since the frequencies of two sinusoid signals are very close, it is difficult to separate them with filtering. Our approach is to design a special sampling method to achieve zero interference under ideal conditions, and estimate the variations of amplitude and phase with statistic approach. It is based on a simple sampling technique, which can reduce the complexity of detection receiver. The algorithm can be applied to remote sensing system and radar system, in order to detect the desired amplitude and phase information.