Abstract: In this paper, based on the field observation experiment in Eryuan,Yunnan Province in 2011 by the C-band Dual-lincar Polarimetric Doppler Radar on Wheel (CPDRW) which was built in the State Kcy Laboratory of Severe Weather(LaSW), Chinese Academy of Meteorological Sciences (CAMS),the influence of beam broadening, beam shielding, ground clutter contamination and attenuation of electromagnetic energy by hydrometcors on the quality of the radar measurement is evaluated by the radar quality-index algorithms that arc able to identify and estimate the amount of contamination.The output result that ranges between zero and one is encoded on a pixel-by-pixel basis into quality-index fields.The more the quality intex is close to zero,the more the radar data arc influenced by each affecting factor, and vice versa.According to the quantitative evaluation results, we can directly understand the affection degree of radar data by each affecting factor and the overall quality of the data, and choose the amount of data and the level of quality used for the different requirements easily.