In this paper,an one-way nested limited area primitive equation model is used to study effects of horizontal resolution on cumulus parameterization.It is found that the change of horizontal resolution has notable effect on cumulus paramerization,and leads to the variation in the forecasted rain field and the synoptic situation.The role of cumulus parameterization in numerical model is also discussed.The results show that,when model horizontal grid length decreased to less than 1.0°,including the cumulus parameterization can increase remarkably correlation coefficient between the forecasted and the observed height field in the lower atmosphere layer,but it decrease evidently in the upper layer.