Abstract: In a 3×3 Latin square design, 6 chosen sheep were divided into 3 groups. The influence of different level of dietary cation-anion balance（DCAB）to parameters of plasma and nitrogen metabolism of sheep fed a wheat stover based TMR diet was researched by feeding and digesting test. The results suggested that the level of DCAB increasing, there were not significant difference between each two groups（P>0.05);concentrations of PUN changed obviously（P<0.05),compared to A and C, B decreased 24% and 26% respectively; contrary to the PUN, the total albumen of plasma present no distinct difference（P>0．05); there were not significant influence on the concentration of Ca, P of blood plasma（P>0．05), but the concentration of Ca decreased gradually, while the concentration of P of B was the highest value, A took the second place , C was the lowest. When the DCAB value was 15 mEq/100 g DM, the deposit rate of nitrogen was the highest, which was advantaged to the utilization of protein. 

Key words: parameters of plasma; nitrogen metabolism; wheat stover; total mixed ratin(TMR); cation-anion balance; sheep 