By analysis of temperature distribution character and rate of selffertilization of Themosensitive Genic Male Sterile (TGMS) rice with low sterile temperature,it is concluded that the beginning day and the last day of the suitable cold waterirrigated for Peiai 64S is the eighteenth day and the third day before panicles headed day ,respectively.The irrigation depth in the first ten days is 15cm,and 20cm in the last five days,which provides theoretical base for the practical production of multiplying with cold waterirrigated.