本文应用微核试验方法对β－胡萝卜素拮抗ＨｇＣｌ_２致小鼠骨髓多染红细胞的微核作用进行研究，结果表明：（１）β－胡萝卜素５ｍｇ／ｋｇ体重及以上剂量时可显著地降低ＨｇＣｌ_２ｌ．０ｍｇ／ｋｇ体重的致小鼠微核作用（Ｐ＜０．００１）；（２）β－胡萝卜素在ＨｇＣｌ２染毒前４ｈ内和染毒后２ｈ内给予小鼠时，均有明显地拮抗致微核作用（Ｐ＜０．００５和Ｐ＜０．００１）；（３）隔日给小鼠β－胡萝卜素２．５ｍｇ／ｋｇ体重一个月后也可明显地减少ＨｇＣｌ_２的致微核作用（Ｐ＜０．００１）. The micronucleus test was used to study the micronucleus effect of β-carotene on HgCl 2 -induced murine bone marrow multi-erythrocytic cells. The results showed that: (1) β-carotene 5mg/kg body weight and above dose can significantly reduce the HgCl_2l . 0 micrograms/kg body weight induced micronucleus in mice (P<0.001); (2) β-carotene was significantly antagonized in mice within 4 hours before and 4 hours after exposure to HgCl2. Micronuclei (P<0.005 and P<0.001); (3) One month after β-carotene 2.5 mg/kg body weight was given every other day, the HgCl_2 micronucleus activity was also significantly reduced (P<0.05). <0.001).