Abstract: This study aimed to determine the optimal time to seed forage grass in Changting and nearby areas,as well as the effects of climatic changes on yield of Chamaecrista rotundifolia and Paspalum notatum,as well as on soil/water conservation.Seeding on March 5,April 12,May 5,and June 11 in 2014 were carried out for the experimentation.Seedling time,emerging rate,coverage area(from August to November),plant height,and yield of the grasses were monitored.The results showed that,as the seeding was delayed,the seedling time of C.rotundifolia and P.notatum shortened,and the emerging rate increased.Nonetheless,both grasses adequately grew through the summer.The grasscoverage was slightly slow initially,but increased and maintained a stable expansion later on.The changes on the plant heights of the two grasses were similar,reaching a maximum when sowed in May,with no significant difference among the treatment groups.The fresh grass yield of C.rotundifoliasowed in May was significantly higher than that sowed in March or April,while that of P.notatumsowed in May was significantly higher than all other times.Thus,it was concluded that May was ideal for seeding the grasses so that their seed germination rate,seedling growth,plant height,grass-coverage,and yield could achieve the optimal levels.