Using the mean monthly precipitation data of recent 14 years at 7 stations in Yemen,seasonal variations of precipitation are studied.On the basis of the analysis on seasonal features of precipitation,interannual variations of summer rain fall are emphatically investigated.Results show that precipitation in Yemen has obviously seasonal changes with large positive anomalies in summer(April to September),especially in July,August,and September,and that the anomalies peak month moves up.In the last 14 years,summer precipitation takes on an increasing dency,which is more obvious in recent years.Summer precipitations anomalies exhibit remarkably interannual variation periods of about 3 and 7 years.