Abstract: Objective To observe the influence of benzene on mouse limb bud development and differentiation and to evaluate the toxicity effect of benzene on limb buds of embr yo mouse.Methods A homeother miarotating apparatus was used to cultivate limb bud at embryomouse aged 12-day to observe the influence of benzene in differet concentration on mouse limb bud development and differentiation.Results the development and differ entiation of mouse forelimb buds were inhibited after being treated with benzene at 75μmol/L and the Neubert score was decreased,wtih the concentration increasing,the inhibitory effect was more conspicuous,and there was a dose-effect relationship.Conclusion Benzene could inhibit the development and differentiation of embryomouse limb bud in vitro.It might be a potential developmental toxic substnce in mince.