To investigate the dissolution character of kaolinite induced by oxalic acids in HAcNH4OAc buffer solution，and the relative contribution of proton and ligand with batch method.The concentration of Al and Si from kaolinite increased with concentration of oxalic acids and acidity of reactive solution and process of reactive time.When the concentration of oxalic acid was 10 mmol/L，acidity of reactive solution was 35，after reaction 1656 hours，the concentration of Al and Si reached a maximum，they were 227 and 186 mmol/L respectively；Ligandpromoted kaolinite dissolution rates（RL）improved with the acidity enhancement;The amplitude of Ligandpromoted kaolinite dissolution evidently improved with the acidity enhancement when the concentration of oxalic acids didnt exceed 1 mmol/L,but the amplitude evidently weaken when the concentration of oxalic acids wasnt less than 5 mmol/L.As far as the contribution of protonpromoted kaolinite dissolution was concerned，the contribution of Ligandpromoted kaolinite dissolution was primary in the range of concentration and acidity of oxalic acids in the experimentation.