Using the physical parameters calculated from data of conventional sounding, model forecast sounding of Beijing rapid update cycle forecast system (BJRUC) and the special sounding constructed from the data detected by microwave radiometer and wind profiler during May to September 2007 and 2008, the difference of the physical parameters between the conventional sounding and the special sounding in the various severe convective weather processes was compared in detail. The availability of the special sounding to discriminate the various convective weather processes was discussed. Finally, the evolution trend of the physical parameters of three kinds of soundings in the hail, thunderstorm, heavy rainfall weather process was analyzed. Through the detailed analysis, some meaningful conclusions have been drawn. Firstly, the physical parameters from special sounding has a same evolution trend as the conventional sounding in different convective weather processes. Moreover, the characteristics of parameters of special sounding are more significant than that of conventional sounding. Therefore it could give a more detailed description of the atmospheric stratification in the convective weather process. Secondly, there has an obvious difference of the parameters of special sounding in the process of various severe weather brewing and development, and it is significant especially during three to six hours before weather occurs. Thus the special sounding has a clear sense to the shortterm nowcasting of various severe weather. Thirdly, in most cases, special sounding could show the evolution of the parameters before and after the severe weather occurs. Model forecast sounding has a better performance, but the evolution of the parameters has a time difference with the observations. The parameters of convectional sounding could not well capture the characteristics evolution during the process of severe weather because of the low temporal resolution. Fourthly, to the thermal parameters, in most cases, there have similar values and the same trends between the model forecast sounding and the special sounding. Therefore, it is needed to revise the quantitative thresholds of the various parameters and then to summarize the screening criteria for severe weather discrimination, which can be used in BJRUC forecast system to give the convective weather classification forecast.