Abstract: Two methods are selected to evaluate economic re- coverable reserves of Shuangyang formation in Changchun oilfield:Economic Limit Water-cut Method and Cash- flow Method.Based on previous foundation,with the combination of available economic parameters and water- flooding curve,the former method can be developed; while for the second method,besides forecasting the pro- duction and waterflood injection,it also takes running cost,related tax expense,different crude oil prices and other economic parameters into consideration.Therefore, by using these two methods together,the economic recov- erable reserves of Shuangyang formation can he effectively worked out,which provides good guidance for later stage development.