Abstract: The river flow of basin has already varied significantly affected by the global climate change and human activity. Based on 28-year (1980-2007) measuring data of river flow, the developing rules of river flow in Shenyang City was studied with mathematically statistics. Results show that the runoff of major rivers in Shenyang City has a decreasing tendency in the past 28 years. The reduction of runoff modulus is between 108-12093m³/(km²·a) with average 2061m³/(km²·a). Pu River has the maximum contribution, Raoyang River the minimum. The mean reduction percentage of 23.11% was caused by human utilization, Liao River, Hun River and Liu River has the more contribution due to more intense human events, Yangximu River the minimum.