Abstract: The recombinant thymosin alpha 1 express in Escherichia coli. According to Escherichia coli codon preference, synthesize Tαl codon and attach them to pMD18-T vector. Insert Tαl ,which was retrieved by two enzymes incide to pET32a , convert Escherichia coli BL21. After the IPTG abduction and 15%SDS-PAGE test, Tαl dissolvability was expressed positively. A positive protein band, which match protein molecular weight about 21.8KDa, was detected in the expression product. The gene of Tαl dissolvability expressed successfully in Escherichia coli expression system.