Abstract: In order to achieve excellent component of lyophilized protectant for chicken alpha- interferon production,lyophilized protectants were screened at first. Secondly,the concentration of protectants and the medium volume were optimized. As the results showed,the mannitol and PEG were selected as the best lyophilized multi-protectants and the concentrations were defined as 3% and 3% respectively. And with the optimized medium volume of 40%,the physical appearance was sponginess and uniform,tabulated,bubble- free and quickly soluble.Under the optimized conditions,the lyophilized recombinant chicken alpha interferon was harvested.The anti- virus activity of alpha- interferon showed no significant difference after 12 months under the temperature at about 40 ℃.This process was successfully established and could be advantageous to its application for chicken alpha interferon production.