Using the conventional observation data, daily precipitation data of manual observation and automatic observation in Hubei Province, NCEP reanalysis data of 0.5°×0.5°, this paper analyzed the effect of frontogenesis function in three intensest rainstorm processes which occurred during the Meiyu period of Hubei Province in June 2011. The results are as follows: (1) The Meiyu process in Hubei in 2011 is of the single blocking high type, presenting three different types of rainstorm processes, during which the frontogenesis appears in the mid level of atmosphere. (2) The frontogenesis of middle atmosphere is mainly triggered by vertical frontogenesis, which is advantageous to the convective precipitation. The frontogenesis of low level is attributed to the horizontal frontogenesis, which was helpful to convey water vapour and convergence lifting. (3) When the middle level frontogenesis occurs after the low level, there will be the long time heavy rain; when the middle level frontogenesis occurs before the low level, there will be short time heavy rain. (4) The vertical frontolysis in low level and the horizontal frontogenesis counteract each other, indicating that the convection in the low level is stable, and the horizontal convergence is not strong, which is not advantageous to occurrence of heavy rains.