In the Ngamoeyeik Irrigation Project Area outside of Yangon City in Lower Myanmar, rainy season paddy cultivation has traditionally been performed from the seedling period in june to the harvesting in November under rain-fed conditions. Summer paddies with irrigation from December to May were added after completion of the project in 1995. However, the project's rainy paddies often suffer from inundation of rain, and the irrigated summer paddies are constrained by limitations in the water-storage reservoirs. To improve this situation, we here propose the development of a paddy cropping schedule for the project, based on our analysis of the 76-year rainfall record at Yangon. The main results of our analysis are as follows:(1) the tendency of farmers to transplant their crops at the end of june, comes from the security of rain water suply, thus increasing the possibility of inundation damage;(2) by shifting the transplatation for the rainy paddies to the end of May, the plant height can be more than doubled, reducing the possibility of inundation damage;(3)such a one-month shift in the transplantation for rainy paddies can be made feasible, even from the viewpoint of water resources management, throught proper reservoir operation.