Abstract: Male sterility of wheat inducing by Chemical hybridization agents (CHA) is one of the main ways to produce hybrid wheat seed. BAU9403 is a new type of CHA which made in China agricultural University. Climatic safety evaluation after spraying with BAU9403 in wheat was studied in this paper. The result showed that the male sterility rate in wheat cultivar Yunong 9901 was 100% when spraying BAU9403 with the dosage of 0.8kg/hm2. A little decrease in male sterility rate was found after five hours when spraying with the water; while no significant decrease in male sterility rate was happened after eight hours when spraying with the water. If raining happened during one to five hours after spraying BAU9403, it is necessary to spraying the CHA with the dosage of 0.2kg/hm2.