VCP11 or VCP21 model lowest switched on 0.5° elevation angle is being applied i n mountaintop radar scanning ways in China now. Contrast analyses are made bet ween the two models and new generation radar of Kunming switched on 0° elevatio n angle through practical detection of a heavy rainstorm case. The preliminary result shows that some mountaintop radars can discover precipitating process e arlier on 0° elevation angle than on 0.5° elevation angle. Remotedetection ef fect of precipitation by mountaintop radar is obviously strengthened on 0° ele vation angle and negative elevation angle. The insufficient of detection ability of mountaintop radar for lowlevel radar echo in routine scan way can be reme died by being switched on negative elevation angle. By using the data obtained f rom other 4 mountaintop radars of Yunnan in experiment, quality comparative ana lysis of lowlevel echo detection is made between the clearday data o btained from mountaintop radar and data of mountaintop radar switched on low e levation angle and negative elevation angle. The results shows that the best low elevation detection angle of mountaintop radar is different owing to the influ ence of surrounding mountains. The suitable low elevation angle in practical wor k should be selected according to related topography.