Aimed atthe stream flow cut-off of Weihe river basin at Huaxian station

it is importantthatthe runoff trend and influence factors are analyzed in this area. According to the data of runoff in Weihe river basin from 1956 to 2000

the changing trend of runoff at Huaxian station is analyzed by using the R/S analysis (Rescale Range Analysis). At the same time

the influence factors of runoff are analyzed. Results show thatthe H urstcoefficientis 0. 778 4

showing thatthe runoff trend is on the persistentdecline. The annual average runoff had been reduced by 3. 79×109m3 from 1970 to 2000

compared to the runoff from 1956 to 1969. Among the influence factors

the reduction influenced by climate is 1. 96×109m3 and the reduction influenced by human activities is 1. 83×109m3

amounting for 51. 7% and 48. 3% of the total reduction

respectively.