Abstract: A ccordiy to the Kuo-Anthes vertical convection and Nordeng slantwise convection parameterization scheme, a vertical-slantwise convection integrated parameterization scheme is designed and introduced into the MM 5 model.Using the integrated scheme, a process of large scale strong precipitation in the Yangtze River Basin in June 1999 is smiulated and tested sensitively.Results show that the intensity and location of precipitation are improved effectively, the vertical circulation forms quickly and intensifies, and the simulated result is close to the observation when the slantwise convective param eterization is introduced into MM 5.The result illustrates the necessity of considering the slantwise convention in torrential rain smiulations for the symmetric instability weather system.