Objective To investigate the influence and mechanism of the products of creatinine metabolites on erythrocytes. Methods Klebsiella pneumoniae were cultured and identified from feces of ureamia patients. The creatininase were isolated.The metabolite and erythrocytes were incubated, hemolysis was observed and GSH was determined in erythrocytes. Results The metabolite can bring hemolysis of erythrocytes (P < 0.05) and GSH in erythrocytes was decreased ( P < 0.001). Hemolysis of erythrocytes can corrected by GSH ( P<0.001). Conclusions The toxicity to demage erythrocytes of the metabolite of creatinine is stronger than that of creatinine. The toxicity can be relieved with GSH. 