The characteristics and technical requirement of a sunphotometer radiometric calibration system, including field and laboratory instruments, has been set up by the international cooperation for high-precision radiometric calibration on the sunphotometer in Aerosol Robotic Network (AERONET). Comparing the calibration results with foreign advanced calibration systems in the same sunphotometer, the accuracy of the proposed system is very high and it is able to calibrate the sunphotometer in AERONET.