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Based on data from the polarimetric radar built jointly by the Zhuhai and Macau meteorological service, the performance of two differential reflectivity calibration methods (vertical incident calibration and solar calibration) is analyzed. Using the meteorological echoes （light rainfall and dry snow） as objects during the operational volume scan，the calibration results are verified, and the sources of calibration errors are revealed. The research indicates that, the solar calibration is quite accurate in calibrating the receiving channels of the radar. After the correction of the system differential phase, the reliable and stable differential reflectivity bias of the radar system can be estimated by implying the strict constraints on the differential phase, reflectivity, SNR, and correlation coefficient when filtering the light rain and dry snow. The biases estimated by light rainfall and dry snow are consistent with that by the solar calibration and show a longterm stability during a period of more than two months. Therefore, it can be concluded that light rain and dry snow calibration is suitable for the online monitoring of the differential reflectivity bias. The verification also suggests that the results of vertical incident calibration deviate from the true significantly. Comparing with vertical incident calibrations of Cband radar in Thurnham of UK and the Nanjing University of China, it is considered that the vertical incident calibration of the ZhuhaiMacau radar is biased by the aviation obstruction light and its maintaining window placed at the top of the radome.