Abstract: Objective：To study the effects of Calcium Pyruvate on the digestion and metabolism of rumen. Methods：The volatility fatty acid (VFA) and NH3-N was measured by GC and colotimetry. The MCP content was measured by G250 colotimetry. Results：The experiment was divided into two successive periods-in vitro and in vivo. Effect of Calcium Pyruvate on rumen digestion and metabolism in vitro was the same as in vivo. Calcium Pyruvate improves rumen digestion and metabolism. in, Calcium Pyruvate of 0.05g/kg BW/d did not change the pH of ruman, and increased the content of acetate (56.91±0.68 vs 61.68±0.79, P<0.01), reduced the rumen degradation of dietary protein (1135.81 ±34.92 vs 1225.05±49.47, mg/L),also reduced the concentration of NH3-N (3.620±0.24 vs 3.540 ±0.13,mM/L). Conclusion Calcium Pyruvate can effect on rumen metabolism.