Studying the impacts of climate change on water resource can help human beings take meas-ures when facing problems.The results of HadCM3 and 7 meteorological sitesdaily data supplied by China Meteorological Administration in Qiantang River Basin are used to estimate design storms in 2020s under A1 B scenario by both dynamic and statistical downscaling methods.The final results show that ex-treme storms will increase in 2020s under A1 B scenario.Besides,the design storms for different return periods calculated through the dynamical method will increase more than those calculated through statisti-cal method.