The heterogeneous nuclear ribonucleoprotein A1(hnRNP A1)was reported to be participated in variety of tumors development.Previously,we isolated an hnRNP A1-specific DNA aptamer BC15,that can evaluate hnRNP A1 expression in liver cancer and inhibit hnRNP A1,which could be a potential drug candidate for hepatocarcinoma treatment.In this study,we found that intrinsic structure formation and sequence composition of the selected DNA aptamer specific to hnRNP A1 are required for the aptamer activity to binding to hnRNP A1 protein and inhibition tumorous cell proliferation.