Abstract: In order to prevent and control the spread of Cenchrus incertus M.A.Curtis in Horqin sandy land,the leaf functional and biological characteristics of Cenchrus incertus.at different growth stages in Horqin sandy land were determined by random sampling method,and the correlation analysis of each character was carried out.The results showed that the specific leaf area of Cenchrus incertus.reached the maximum at seedling stage,which was 333.43 cm2·g^-1;the leaf area reached the maximum at flowering and fruiting stage,which was 8.03 cm~2 per piece;the leaf dry weight reached the maximum at tillering stage,which was 0.028 g per plant;the whole plant biomass reached the maximum at flowering stage,which was 7.34 g per plant;the contribution rate of leaves to the whole plant at tillering stage was the largest,which reached 40.12%.In the mature stage of Cenchrus incertus.,the percentage of panicle biomass was significantly higher than that of leaf biomass;leaf area was the most important promoting factor to control the growth of whole plant biomass;leaf dry weight was the most important inhibiting factor to control the growth of panicle biomass.