A field experiment was conducted to study the effects of different sowing rates (22.5, 30.0, 37.5, 45.0, 52.5, 60.0 and 75 kg/hm²) on the growth, grass yield and nutrient accumulation of late-sowing Chinese milk vetch (Astragalus sinicus L.). The results showed that with the increase of sowing rate, the number of emerged seedling per hectare increased significantly, however, the fresh and dry weights per plant decreased with the increase of sowing rate in the range of 30.0-75.0 kg/hm² , and there was no significant difference in the number of branches per plant among different treatments. Fresh and dry yields increased at first and then decreased with the increase of the sowing rate. The highest yield of (48.34 t/hm² for fresh yield and 5.70 t/hm² for dry yield) was obtained when the sowing rate was 45.0 kg/hm².The contents of C, N, P and K in the shoots were insignificantly different between different treatments, while nutrient accumulation was increased in the beginning and then decreased with the increase of sowing rate. The highest nutrient accumulation was obtained when the sowing rate was 45.0 kg/hm², and no significant difference was found when sowing rate increasing further. Therefore, it is concluded that the suitable sowing rate of A. sinicus in late sowing is 45.0 kg/hm² which can get the higher grass yield and nutrient accumulation.