Because of several advantages such as low cost, simple culture, and high growth rate, bacterial systems, in particular Escherichia coli, are the main expression system for production of recombinant pharmaceutical proteins. In this research, we used this system to produce a valuable human growth factor, somatomedin C. cDNA of this gene was prepared and cloned into an expression vector using NdeI and BamHI restriction sites. The cloning process resulted in the generation of a recombinant vector in which the somatomedin cDNA was placed under control of the T7 inducible promoter. This recombinant vector was introduced into the E. coli and the protein expression was evaluated following induction with 1 M IPTG solution. The results showed that transgenic bacteria produce noticeable amount of human protein after 22 hrs induction at 25 degree centigrade.