Based on the local chronicles in the lake district, the historical flood years in Poyang Lake in the past 600 years are deferred.The characteristics of the heavy flood and heavier flood occurrences are statistically analysed.The heavier flood occurrences can be summarized into three stages, namely, active (frequency P>0.416), normal (P<0.231) and interval stages (0.231≤P<0.416), as a result of which 3 active periods, 2 interval ones and 7 normal ones are obtained.Statistics also shows that both the heavier flood and heavy flood occurrences tend to mcrease with a tendency rate of 0.042 a/10a and 0.066 a/lOa, respectively.The regularity of seasonal and yearly changes are given.The historical evolution of the heavier flood occurrences in 1401-1990 has been simulated, showing a wavy fluctuation with 2 crests and 2 troughs.