ased on the data about waterlogging and drought, referring agricultural disasters,capability of preventing flood and developing feature of crops,the indexes on drought and waterlogging are determined for each season. The results show that,in the last 40 years or more,disastrous years exceeded the normal, and damages caused by waterlogging are more serious than that by drought. It is of momentous significance for adopting measures of defense,avoiding darnage and developing agriculture to understand and master the weather/climate regularity on drought and waterlogging.