Abstract: Objective To verify the pathogenicity of overwintering variant and resuscitat ing strains of vibrio cholerae O1 of the bioty peE1T or,in order to furnish evidence for prevent to cholera.Methods Adopt micr obiologic PCR techniques and traditional suckling mouse and rabbit as animal model.Results CT gene was maintaining in the cell of each stage in the over-wintering progress,but the toxicity was lower in the test of rabbi-tlagatedileal loops.In the resuscitative progress,cell's surface structure were resumptive,the tox in was constantly raised.The toxicity of the recovered strain was reached or iginal standard as well.Conclusion All the variant strains of vibrio cholerae biotype E1T or were possessed some toxicity,and can be recovered to original epidemic strains,therefore must be paid attnetion to monitor the overwintering strain in preventing cholera.