Abstract: Kunming mice were chosen to administer by intragastric administration in this study. We evaluated the effect of the Sulfamethazinum to subchronic toxicity, bone marrow cell micronucleus and spern abnormality on mice. In subchronic toxicity test, the difference of weight changes of mice in high dose group and middle dose group were lower obviously than the control group and the low dose group(P＜0.01). The organ coefficient of heart of the male mice in high dose gorup were lower obviously than the control group and the low dose group(P＜0.05).The organ coefficient of kidney of the male mice were lower obviously than the control group(P＜0.05). The organ coefficient of kidney of the female mice in high dose group were lower obviously than the control group and the low dose group(P＜0.05). In bone marrow cell micronucleus test, high dose Sulfamethazinum group had significant difference compared with blank control group(P＜0.05),but there were no significant difference in high, middle and low dose of Sulfamethazinum groups. And in sperm abnormality test. the high and middle dose groups had very significant higher rate than blank control group(P＜0.01), the low dose group had significant difference compared with blank control group(P＜0.05), the high dose group had significant higher than the middle and low dose group(P<0.05). The results indicated that the high dose of Sulfamethazinum group affected the heart, kidney and bone marrow cell micronucleus on mice, the middle dose of Sulfametazinum group had the influence on bone marrow cell micronucleus of the male mice, the high, middle and low dose of Sulfamethazinum groups had the effect on the sperm abnormality.

Key words: Sulfamethazinum; subchronic toxicity; micronucleus; sperm abnormality