Abstract: The variety Paspalum atratum cv. Reyan 11 is most significant as forage in southern China. For improving seed production technology and varietal improvement by hybridization technology, the author studied the flowering behavior of Paspalum atratum cv. Reyan 11 by observation individual plant and inflorescence. The result showed that the flowering period of single inflorescence lasted for 6 to 9 days.Blooming peaking in a day is between 9 and 13 o'clock, with 93.6% of whole bloom. The most suitable to match temperature for blooming is between 33℃ to 37℃ , and the most suitable to match degree of humidity for blooming is between 60% to 70%.In order to increase seed production, the seed field should be located area with air temperature between 33℃ to 37℃, and degree of humidity between 60%to 70% in the flowering stage. The crossing day should be in 2nd to 4th after opening flower stage, and the crossing time should be between 9h and 13h.