This article focuses on the application of the 2013-2015 Beijing meteorological tower data and derivative data, combined with conventional and unconventional observation data, such as VDRAS, automatic weather stations and NCEP reanalysis data. According to the evolution of the boundary layer elements, shorttime heavy precipitation is divided into two types, one has the surface convergence line and the other has not. And we also focus on the evolution of the boundary layer elements of the two types shorttime rainfalls to find the forecasting signal before heavy rainfalls occur in summer, which could provide reference for the shorttime heavy rainfall forecasting. The results show that varivation of the elements of the meteorological power can not predict for the occurrence of the nonsurface convergence line type, but it has certain guiding significance to the shorttime severe rainfall of the surface convergence line type. Before such type of heavy rain occurs, the temperature and potential temperature begin to decrease obviously and decline rate gradually increases. The temperature change rate gradually increases to -0.35℃ per minute. The specific humidity increases significantly 3 h before the start of the heavy rainfall below 325 m. When it begins to rain, the specific humidity decreases about 3.5 g·kg-1 during 20 min before the rainfall begins. The lowlevel wind shear is up to the strong degree. But the specific humidity and lowlevel wind shear can show the signals at 10-20 min lead time. So the evolution of tower meteorological elements and the physical quantities have indicative meaning for the forecasting and warning of shorttime rainfall of surface convergence line type.