Abstract: Objective To study the effect of BCL-2 gene on skin carcinogensis due to arseniasis caused by coal-burning.Methods　Patients with arseniasis caused by coal-buring were divided into carcinoma group(A group,18 cases),pre-carcinoma group(B group,11 cases)and common pathological changes group (C group,39 cases);immu-histochemistry of two steps was used to determine BCL-2 protein.Results　Among A、B and C group,the positive cell density were(45.97±14.29),(33.20±15.16) and(22.74±15.38);the positive percentages were 94.44%、 90.91% and 58.97% respectively.Whether positive cell density or percentage,the differences had statistical significance between A and C groups(P<0101)or B and C group(P<0.05).The difference of grade constitution also had statistical significance(P<0.01);gradeⅢmade up 50%in A group,but 9.09% in B group and 2.56% in C group.Conclusion　BCL-2 gene may take a positive effect on the development of the disease;its detection has pratical value for judging whether the focus of skin due to this disease is malignant or benign.