Abstract: Objective To study the optimal expression and purification condition of the derivate of GLP-1.Methods By PCR technology synthetizing the gene of the derivate of GL P-1 with preference codon of E.coli and the plasmid containing GLP-1.Expressed fusion proteins were purified and desalted with Ni-NTA column and C18 Sep-Pak column,respectively.After chemical cleavaged by formic acid hydroformicant,the hydrolysis products were purified and prepared with Ni-NTA column and HPLC.The target peptide was identified by mass spectrum.Results In BL21 the optimal expression condition as follow:inducing temperature was 37℃,inducing time was 6 h,and the concentration of the IPTG was 016 mmol/L.The optimal chromatographic condition of getting HPLC as follow:30 min of the linear gradient elution,from 10% to 70% for mobile phase A(100% CNCH₃),from 90% to 30% for mobile phase B(100%H₂O,0.1% TFA),flow rate was 1 ml/min,and the detection wave length was 280nm.The molecular mass of the derivate of GLP-1 was 5 548 Da through mass spectrum identification.Conclusion With the optimal expression and purification condition,the high yield and high purity(>98%)derivate of GLP-1 can be obtained.