In this work, reduced graphene oxide loaded flower-like bismuth subcarbonate composite (Bi2O2CO3-rGO) has been successfully synthesized by a facile hydrothermal method. The prepared Bi2O2CO3-rGO as modification composite was applied to construct voltammetric sensor for the first time. The Bi2O2CO3-rGO modified glassy carbon electrode (Bi2O2CO3-rGO/GCE) exhibited highly sensitive response to urapidil. The electrochemical behavior of urapidil was studied in detail. Under optimum conditions, a lower detection limit (1.5 x 10(-9) mol L-1) and wider linear range (5.0 x 10 mol L-1 x 10(-6) mol L-1) were achieved by the proposed sensor. Finally, the proposed method was applied to the analysis of real sample, and the results showed applicable and reliable.