Through analysised of normal traffic and attack flow

statistic result showed that the normal traffic throughout had an obviously degrade and attack flow had a short time abnormity pulse with higher amplitude.An approach of de-tecting LDoS attack based on time window statistic was presented.Experiments on different length of sample time were conducted in a test environment established on simulation network.Test results show that the detection probability is more than 96%

false negative and false positive are less than 3%.