An assessment approach is proposed to understand the aquatic effects of watershed socio-economic development in order to support Lake Dongping watershed management and its potential solution is identified for joint-mitigation of socio-economic impacts. Different with traditional studies, this integrated framework, including PSR-based assessment, system dynamics and scenario analysis, identifies the current status, future trend and its limited indicators as well as the potential, direction and threshold of joint-mitigation. The results indicate that (i) the assessment index for Lake Dongping was increased from 52.4 (level Ⅲ) at 2000 to 61.6 (level Ⅱ) at 2010, however, the future trend would be decreased slowly in next 20 years and stay at level Ⅲ or IV for a long time if keeping current high-speed developing rate and control levels,(ii) it was essential to reduce the developing rate at 2030 as about 75% of average value in past 11 years and to improve the environmental protection as level I required by assessment criteria; and (iii) the roadmap for Lake Dongping watershed should pay more attention to the pollution reductions of current and potential sources following by natural restoration.