Abstract: Based on forage grading index（GI2001）proposed by Prof.LU De-xun in 2001,in this study we selected new parameters and attempted to establish a new forage grading index（GI2008）for cows in 2008.In order to confirm the rationality of GI2008,GI2001 and RFV were used to evaluate four forages quality and the results were compared.The values of GI2001,GI2008 and RFV were calculated according to their formulas,respectively.The results showed that the values of GI2008 for the 4 forages ranked as follows：alfalfa（145.50）corn silage（108.44）chinensis（20.10）corn stalk（12.09）;the values of GI2001 ranked as follows：alfalfa（32.11）corn silage（19.70）chinensis（9.39）corn stalk（3.98）;the values of RFV ranked as follows：alfalfa（109.20）corn silage（100.12）chinensis（91.55）corn stalk（69.93）.The sequences of the quality of four forages were identical by GI2008,GI2001 and RFV methods.GI2008 and GI2001 were superior to RFV,and both of them could be used to evaluate the forage quality scientifically.The regression equation obtained between GI2001 and GI2008 was as follows：Y=5.1669X-12.683（R2=0.946 3,P0.000 1,n=4）.GI2001 is simple and easy to operate,but GI2008 is more scientific than GI2001 when using for research purpose.Thus,GI2008 can more accurately and scientifically evaluate the quality of forages on research in future.