The role of sulfuric acid in the chemical weathering of carbonate rock and its influences on the regional carbon cycling have been recognized as important issues for global climate change. One small drainage basin in North China named Qin River was selected in this study. The contributions from potential sources to the dissolved component were calculated based on chemical compositions of river water. Carbon isotopes of dissolved inorganic carbon were also used to verify the chemical weathering by sulfuric acid. The results demonstrated that Calcium and Magnesium were the dominant cations,and biocarbonate and sulfate were the dominant anions in the river water; Dissolved cations of river water were mainly controlled by carbonate weathering, atmospheric inputs,and evaporate dissolution with mean values of 48.5%,35.3%,and 14.1%,respectively,while minor controlled by silicate weathering and human inputs which accounted for 1.7% and 0.6%,respectively; The chemical weathering rates of carbonate,silicate and evaporates in Qin River basin were estimated to be approximately 8.41,0.07 and 2.43 t·km~(-2)·a~(-1),respectively,and CO_2 consumption rates for carbonate and silicate were 1.43*10~5 mol·km~(-2)·a~(-1) and 0.03* 105 mol·km~(-2)·a~(-1),respectively; and CO_2 released from carbonate chemical weathering by sulfuric acid was estimated to be 0.60*10~5 mol·km~(-2)·a~(-1) lower than the results obtained in karst regions in South China. South China probably due to different climate and occurrence and content of sulfide.