Abstract: Accurate identification of reflected wave phase pP or sP is of great importance in precise determination of focal depth. Using seismic wave data recorded by Hotan, Xinjiang, seismic array, we apply F-detection algorithm to identify pP or sP phase on P-wave seismograms of 3 earthquakes, of which the epicentral distances are 22.1deg;,6.44deg;and 39.62deg;, respectively. The study result indicates that the F-detection algorithm is helpful in relatively accurate identification of pP or sP phase. To verify the validity of F-detection algorithm, we use it to analyze the wave data of central distance 22.1deg;event with additional different level noises. The result indicates that pP or sP phase can still be identified.