In order to analyze the difference of optics sizing and aerodynamic sizing of aerosol particle, a method for revising the aerodynamic sizing using optics method is proposed. The method uses the measurement results by an Aethalometer (AE), an Optical Particle Counter (OPC) and an Integrating Nephelometer(IN)to revise the aerodynamic sizing of aerosol particle measured by 3321 in Xiamen. The comparisons with other instruments show that the method is satisfactory. Lastly, the reason for difference of optics sizing and aerodynamic sizing is analyzed.