Abstract: Objective To study the toxicity of samarium nitrate on male mice's testicle tissue.Methods Samarium nitrate was administrated to mice at different doses(0,5,50,500,2 000 mg/L)for 90 d.The contents of samarium and trace elements in testicle were observed.Results Samarium were accumulated in 50,500 and 2 000 mg/L.The contents of Zn and Cu in testes decreased significantly.And there was a dose-response relationship between dose logarithm of samarium nitrate and content of Zn,while content of Coincreased largely.Conclusion Samarium nitrate exposure could destroy blood-testis barrier,cause samarium accumulation in testes and metabolism unbalance of trace elements,serious damage to male reproductive system of mice accordingly.