AIM To explore the mercury accumulation in KM mice after being given Zuotai at different doses and time.METHODS KM mice were randomly divided into blank group,Zuotai low-,middle-and high-dose (6.07,60.70 and 606.97 mg/kg,42 d;606.97 mg/kg,14 d) groups.The mercury contents in brain (olfactory bulb,cortex,hippocampus,hypothalamus,brain stem,cerebellum),heart,lung,kidney,liver,spleen,serum,muscle of mice were measured after administration.RESULTS Compared with the blank group,Zuotai at low-dose significantly increased the mercury contents in hippocampus,cerebellum,lung,kidney,liver and serum of mice after 42-day treatment;Zuotai at middle-dose markedly increased the mercury contents in olfactory bulb,cortex,hippocampus,brain stem,cerebellum,heart,lung,kidney,liver,spleen and serum of mice after 42-day treatment;the mice treated with high-dose of Zuotai for 42,14 days significantly increased the mercury contents in olfactory bulb,cortex,hippocampus,hypothalamus,brain stem,cerebellum,heart,lung,kidney,liver,spleen,muscle and serum.CONCLUSION Mercury can be accumulated in different tissues of mice after intragastric administration of Zuotai in a dose-and time-dependent manner,which suggests that Zuotai and its compound preparations should not be used in high-dose and long-term.