Analysis of the rules for runoff evolutionof Kwanza River under the background of climate change is of significant importance to the multipurpose use of water resources in Angola.This paper, based on the natural runoff data of Cambambe Hydrometrical Station, analyzed the runoff variation trend and abrupt change characteristics, and came to the following conclusions:(1) the annual runoff and wet-season runoff presented an insignificant trend to decrease; (2) the dry-season runoff presented a significant trend to decrease, which would intensify the runoff difference between dry season and wet season within the year and impose negative effect on the multipurpose use of water resources if such trend lasts; (3) abrupt changes of annual runoff and wet-season runoff occurred in 1970 and 2001, and those of dry-season runoff occurred in 1971 and 2004.The variation trends of both the previous and following sequences of the abrupt change became different.