Abstract: To study the ruminal and small intestinal digestibility of Shandong province mainly concentrates for sheep，in this experiment, ruminal digestibility and small intestinal digestibility of rumen undegraded protein (RUP) of Shandong Province mainly concentrates for sheep were measured by mobile nylon bag method (MBT) and modified three-step in vitro method (MTSP), and regression analysis between small intestinal digestibility of RUP and conventional nutrients were carried out. The results showed as follows: (1) In the dry matter and crude protein ruminal digestibility of the measured feed, wheat (82.47% ,83.79% ) was the highest, whole cottonseed (51.33% ,54.12% ) was the lowest, in the small intestinal digestibility of RUP, corn gluten meal (98.95%) was the highest, wheat bran (74.34%) was the lowest. (2) The regression equation of crude protein ruminal digestibility (Y) and dry matter ruminal digestibility (X) was: Y=11.62+0.88X (R₂=0.933, P＜0.05); The regression equation of the small intestinal digestibility of RUP (Y), crude protein content (X₁) and neutral detergent fiber content (X₂) was: Y=85.57-0.28X₁+0.24X₂(R₂=0.873,P＜0.05). In conclusion, it was feasible that using conventional feed nutrient content to predict small intestinal digestibility of RUP.