Abstract: Based on the research on phase characteristics of the line spectrum of ship propeller noise and shafting noise, it is found that there is a relatively stable phase difference between shaft frequency line spectrums of propeller noise and shafting noise. Therefore, the phase difference is proposed to be a new ship recognition feature. The feasibility of phase difference extraction is verified by modeling and simulation, and a method for extracting phase difference between shaft frequency line spectrum of propeller noise and that of shafting noise is proposed. The phase difference feature of experimental ships is extracted from the obtained radiated noise data. The stability and discrimination of phase difference feature are studied among different individual ships at different speeds with specific time length noise. The results show that the phase difference feature has good stability at different speeds and good discrimination among different ships of the same type. It could be a new method for ship target recognition.