Abstract: The aim is to ensure optimal sowed period of the grass sorghum Focao No.1 in the Pearl River Delta in the study. The Focao No.1 was sowed with different time, and biologic yield and fruits yield respectively was detected after the trial The result showed that its biologic yield was higher than that of others on 30, April, but the fruit yield was higher than that of others on 10, May. Accordingly, the optimal sowing period should be ensured according to the demands.