The ratio between stratiform and convective precipitation simulated by the NCAR CCM3 is examined. Stratiform rain only accounts for about 1.5% of the total rain amount in CCM3 between 20¿N and 20¿S, far lower than 40% estimated from Tropical Rainfall Measuring Mission (TRMM) data. Preliminary study suggests that the serious underestimation of stratiform precipitation in CCM3 could be responsible for failed simulations of intraseasonal oscillation (ISO) and seasonal migration of the intertropical convergence zone (ITCZ) precipitation across the equator. Sensitivity experiment with artificially enhanced stratiform precipitation indicates that increase of stratiform rain fraction can improve the simulations of ISO and seasonal migration of the ITCZ precipitation. This study suggests that reasonable partition of stratiform and convective precipitation is crucial for a climate model to project realistic climate features.