The objective of this study was to evaluate CPM model in terms of improvement in performance of lactating cows by balancing dietary energy and protein. Fifty-six dairy cattle with similar lactation, age, body weight and health were selected, and average daily milk yield of half of cattle was about 20 kilograms, and that of another half was about 25 kilograms. According to matching experiment design, control diets were the diets of dairy farm, experiment diets were the diets adjusted by CPM model. The application effect of CPM model on evaluating diets and predicting the dairy cattle performance was examined by feeding trial. The trial lasted for 45 d. The results showed that, milk yield, 4% fat corrected milk yield, blood urea nitrogen （BUN） and milk urea nitrogen (MUN) contents in milk of the dairy cattle fed the adjusted diet were all slightly higher than those in control group (P>0.05). The milk fat rate in experimental group Ⅰ was slightly higher than that in control group Ⅰ (P>0.05), but both had similar milk protein rate. The milk fat rate and milk protein rate in experimental group Ⅱ were slightly lower than those in control group Ⅱ (P>0.05). Cost of the adjusted diets was decreased by ￥2.43/d and ￥2.12/d compared with original diets, respectively. The experimental results proved that error margin between milk yield predicted by CPM model and dairy cattle actual milk yield was in the range of 6 percentage except control group Ⅰ, and the error margin between DMI predicted by CPM model and actual DMI was in the range of 5 percentage. In conclusion, the CPM model could accurately predict diet nutritive value and improve diet energy nitrogen balance and increase diary cattle performance and decrease feeding cost. So it is feasible to apply CPM model in China large-scale dairy farms.［Chinese Journal of Animal Nutrition, 2010，22（2）:310-317］