Abstract: Abstract: 【Objective】Study and promotion of green scale beef cattle feeding technology， development of Green Growth microecological feed additives,To study their impact on beef cattle serum physiological and biochemical indicators。【Methods】Isolation and screening of the three have bacteria for Preparation of Microecologics，Selection of conditions consistent beef cattle，To study the physiological and biochemical indicators of serum impact。【Results】The experimental results show that，Isolation of bacteria and Preparation of Microecologics to meet the standards, Beef cattle serum hyperthyroidism or the lower three key indicators (FT3, FT4, TSH), in beef cattle before and after the experiment is a change in the normal range, serum growth hormone and insulin-like growth factor Content higher than control group, But the difference was not significant (P> 0.05). 【Conclusion】The results suggest that microecological feed additives for beef cattle serum on the physiological and biochemical indexes without adversely affecting, it is safe to green feed additives。