Abstract: In order to obtain antimicrobial peptide efficiently,the recombinant expression of antimicrobial peptide target gene Tachyplesin Ⅰ(TP1)in Escherichia coli BL21(DE3)was studied. The expression vector pET32a-TP1 was constructed and converted to Escherichia coli BL21(DE3). IPTG induced the expression of target genes,and the fusion protein was purified by NI-NTA affinity chromatography. The purified TrxA-TP1 fusion peptide was released by hydroxylamine and recombinant TP1 was analyzed by mass spectrometry. Results showed that TrxA-TP1 fusion protein was induced successfully with IPTG at 37℃. The molecular weight of TrxA-TP1 was about 20 kDa. The recombinant TP1 obtained by hydroxylamine cleavage showed strong antibacterial bioactivity against S.aureus and B.subtilis,The minimal inhibitory concentration was 6 and 10 mg/L respectively. These experiments established a useful system for further studies,application and mass production of antimicrobial peptide TP1.