Abstract:The fertility transfer character of Tianfeng A and seed production site selection were studied in order to solve the insecurity problem of seed production for Tianyouhuazhan, a hybrid seed combination. A new idea for determining appropriate region and period for seed production was proposed according to the climate data together with the demand of safe-period in seed production. A computer system was utilized to analysis the meteorological dam of 50 years in China. The result indicated that the critical temperature of sterility transfer for Tianfeng A was about 27.8 ℃. It showed the safe production of Tianyouhuazhan seed was different from location to location. According to historical meteorological data, the risk probability of three safe periods of Tianyouhuazhan seed production, e.g. Sanyan of Hainan province, et al, were selected as the suitable seed production for Tianyouhuazhan combination. Hence, the security of Tianyouhuazhan seed production could be guaranteed on the basis of scientific selection of sites and time for seed production. In 2013, we attempted to produce the seed of Tianyouhuazhan in Sanya, Hainan province via the computer- aided selection system, the grain yield could reach 3 750 kg/hm2. The results suggested that the problem of low security for Tianyouhuazhan seed production could be solved by this method, and it could provide a useful technical support for the development of hybrid rice.