Abstract: Objective: To study the correlations of the expressions of nm23 and bcl-2 genes with the invasion and metastasis in papillary thyroid carcinoma(PTC).Methods: The expressions of nm23 and bcl-2 were detected by immunohistochemical SP method in the thyroid tissues from 157 papillary thyroid carcinoma and 30 thyroid adenoma.Results: The positive rate of nm23 expression in PTC group was higher than in thyroid adenoma group(P<0.05);the positive rate of nm23 expression with neck lymph node metastasis was lower than in the group without neck lymph node metastasis(P<0.01);with the increase of PTC tumor pathological grade,the positive rate of nm23 expression was decreased(P<0.01).The positive rate of bcl-2 expression in PTC group was higher than in thyroid adenoma group(P<0.01);the positive rate of bcl-2 expression with neck lymph node metastasis was higher than in the group without neck lymph node metastasis(P<0.05);with the increase of PTC tumor pathological grade,the positive rate of bcl-2 expression was increased(P<0.01).Conclusions: The expressions of nm23 and bcl-2 gene are closely correlated with the invasion and metastasis in PTC and the papillary thyroid carcinoma's metastasis is positively correlated with bcl-2 expression and negatively correlated with nm23 expression.