Ocean waves are generally a mixture of wind-wave and swell.Due to the significant differences in their growth，decay，propagation，and destruction mechanisms，the separation of wind-wave and swell is of great significance for marine research and engineering application.Based on the measured data in the offshore of Hambantota，Sri Lanka，this paper discusses the selection of the wave age threshold in the traditional methods and analyzes the wave characteristics of the offshore of Hambantota.Finally，the method based on wave age is used to verify the newly proposed method based on the overshoot phenomenon that does not rely on meteorology information.The results show that the optimal threshold of wave age is 1.7.The offshore of Hambantota is dominated by the swell propagating from distant storms.The method based on the overshoot phenomenon is consistent with the method based on wave age in the identification of the swell propagating from distant storms but gives different results for the wind-wave and local swell at the high frequency，which can be explained by the fact that the change of physical wave characteristics is slower than that of wind.