For the production of ${alpha}$-amylase cloned from Bacillus licheniformis expressed in E. coli, cultivating factors including the concentrations of glucose, maltose and acetic acid were investigated. The results were as follows: 1) Maximum ${alpha}$-amylase yield and maximum specific production rate obtained from glucose source were better than those achieved from maltose source. 2) The optimum production yield of ${alpha}$-amylase was obtained at 1.0ml/$ell$ or less of initial acetic acid concentration.