We here investigate the statistical characteristics of ocean waves and surges over Taiwan waters by cluster and return period analysis. The results of cluster analysis show the data records from neighbor stations would not be always fall into the same cluster due to the influence of topography around wave stations. In addition to, the wave height of the specified return period is significant related to the probability distribution of the data set. Because of the extreme wave record in Gueishandao sea area around Taiwan, the suitable probability distribution can not be well determined in this area. It would affect the wave height analysis of the return period. We would continue the study to discuss the suitable probability distribution, so as to determine the accurate wave height in different situations of the specified return period.