When being planted in wide areas in southern China (23°23′–33°23′ N, 98°35′–120°19′ E, sea level above 2.7–1285 m), Liangyoupeijiu (LYPJ), a two-line hybrid rice combination, showed a seed setting rate of 75.2–77.2%, which was lower by 4.3–7.5 percent point than that of an indica hybrid rice Shanyou 63 (CK), with similar values of grain yield and coefficients of variation to CK. Sowing during 5-25th of May in Nanjing (32°3′ N, 118 °48′ E), China, LYPJ headed before 4th September, and gave a seed setting rate of 75–90%, and grain yield over 1 kg/m². If the sowing date was delayed to 14–15th, June, its heading date would be as late as 17th–21st September, and seed setting rate would be declined by 10–15% in comparison with that on a suitable sowing date. When flowering took place at an average daily temperature range of 13.7–28.5℃ for five days, the spikelet fertility (SF) would be increased by 1.9–10.7%, for each increment of 1℃. The suitable (SF≥90%) and safe (SF≥75%) temperatures for flowering stage were indicated to be 26.5℃ and 22.9℃, respectively. To get a high and stable seed set in cultivating LYPJ, it was recommended that LYPJ would be planted in the areas south of 34°N, and the favorable average daily temperature during flowering stage should be at 26–28℃.