From March to November 2019,the largest on-station comparison observation calibration (OCOC) in China was carried out so far,based on the mobile REAL standard aerosol lidar certified by the European lidar calibration center.In this paper,a method for OCOC is firstly introduced.Then,the first OCOC between REAL lidar and 12 aerosol lidars distributed in Beijing,Shanghai and Guangzhou were carried out separately at 532 nm wavelength.The 11 radars which were calibrated in advance according to method of hardware and software calibration established by the meteorological observation center (MOC) were quantitatively evaluated according to the preset quality criteria,and the results show that the 11 radars basically meet the requirements.The system deviation (SD) of 9 radars P/S channels within a range of 2—5 km was all in ±20%,and the SD of more than 50% of the calibrated radars P channels within a range of 0.5—2 km is basically in ±10%.The main problems are P/S channel crosstalk and detector saturation,etc.This work determines the reliable range of data of calibrated radars and provides support for operational quantitative application of aerosol lidar.