利用东江中下游河源和博罗站1956~2005年径流资料，采用线性倾向估计、滑动平均、滑动t检验、有序聚类等方法，分析东江中下游年、季节径流量的变化趋势和突变特征，结果表明：1) 河源站和博罗站年径流量分别呈不显著的增加和减少趋势，径流量倾向率分别为0.38亿m3/10a、–0.46亿m3/10a；2) 东江中下游春季和冬季径流量呈现不显著的增加趋势，而夏季和秋季径流量则呈现不显著的减少趋势；3) 河源站年径流量和河源站、博罗站的冬季径流量发生了明显突变，其中河源站年径流量突变出现在1972年，而河源站和博罗站冬季径流量突变主要发生在20世纪70年代初。 Based on the monthly runoff data of the Heyuan and Boluo station in the middle and lower reaches of Dongjiang River from 1956 to 2005, changes trend and abrupt changes of runoff variation were analyzed by the methods of linear trend analysis, moving average, moving t-test, Yamamoto and sequential cluster analysis. Some important results were obtained in three aspects as follows. 1) The annual runoff at the He-yuan and Boluo station had an unobvious increase and decrease trend, respectively, and change tendency rate of them were 0.38 × 108 m3/10a and –0.46 × 108 m3/10a, respectively; 2) The spring and winter runoff in the middle and lower reaches of Dongjiang River had an increase trend, while the summer and autumn runoff had an decrease trend, but they did not arrive at α = 0.05 statistically significant level; 3) The annual runoff at the Heyuan station as well as winter runoff at the Heyuan and Boluo station had significant abrupt changes. The abrupt changes of the annual runoff at the Heyuan station occurred in 1972, while winter runoff at the Heyuan and Boluo station had significant abrupt changes in the early 1970s