It was reported that P-L promoter and alkaline phosphatase (phoA) signal peptide were used to construct secretory expression plasmid suitable to express glucagon and [Des-His(1)] glucagon in E. coli BL21 herein. Expression studies showed these two peptides could be expressed and secreted into the culture medium. The expression yield of recombinant glucagon reached 3.46 mg/L/OD600 unit of cells in shake flask. The yield of [Des-His(1)] glucagon was found to be higher than that of glucagon. In addition, some factors involved in secretion were studied too.