The influences of zinc metallothionein(ZnMT) induced by Zn on mice erythrocyte membrane configuration, membrane sulfhydryl content, membrane fluidity, membrane permeability and so on after methylmercury (MeHg) treatment were studied, the protection of ZnMT against the membrane damage of MeHg was studied. The results showed that Zn could induce the production of ZnMT in the liver of mice. With the increase of Zn content, the level of ZnMT increased and had dose-effect relationship between them (r = 0.996). ZnMT could protect membrane configuration and -SH and prevent the damage of MeHg on the membrane fluidity and permeability. The results also showed that the dose of Zn administered to mice should be appropriate. High doses of Zn could cause damages.