Waves that have propagated out of their generating fetch are called swell. Swell waves can significantly affect offshore structure designs, small boat operations and ship passages over harbor entrance, and surf forecasting. It is necessary and interesting to be studied on both scientific and practical purposes. There are several typhoons affect Taiwan every year. This paper estimates swell height by using a wind-sea and swell separation approach. The purpose of this paper is to understand the relationship between typhoon tracks and their generated swells. It is found that the value and occurrence time of maxima swell height are related to typhoon track. The maxima swell heights that generated by typhoons move westerly to Taiwan (track category I, III, V) is much larger than them generated by the typhoon moves from low to high latitute (track category VI). The maxima swell height estimated in this paper is up to 7 m. In addition, the maxima swell heights always occurr after typhoon passing. In this study, it is also found that even the typhoon is far, the generated swell may have the same level as it generated by close typhoons. The results presented in this paper are obtained by analyzing the wave data from Taiwan coast ocean and may helpful on the prediction of typhoon swell.