Abstract: In this study, the separation and purification method of polypeptide (-Glu-Cys)n-Gly in algae was developed. The polypeptides concentration in kelp was determined by reversion phase C18-high performance liquid chromatography with fluorescence detector. The kelp was induced by Zn2+ under different concentrations, the enrichment ability for Zn2+ and the variation trend of H-(-Glu-Cys)2-Gly-OH(PC2), H-(-Glu-Cys)3-Gly-OH(PC3) and H-(-Glu-Cys)4-Gly-OH(PC4) were also studied. Results showed that the three compounds were well separated with retention times between 16.6 min and 20.2 min. The high performance liquid chromatography method had good linear correlation coefficient(r0.9995), low limit of detection and good reproducibility(RSD2%). The kelp had a stronger enrichment ability of Zn2+. The content of Zn2+ in algae increased obviously with metal concentration and inducing time increasing. The concentration of PC2、PC3 and PC4 in algae increased slightly with metal inducing time increasing, and the content of polypeptide presented a positive correlation with Zn2+ concentration.