OBJECTIVE To evaluate clinical significance of HIF-1 alpha,VEGF and VEGF-C expression in papillary thyroid carcinoma. METHODS HIF-1a,VEGF and VEGF-C expression were detected by immunohistochemical method in 73 patients of papillary thyroid carcinoma(group I ), 32 patients of thyroid adenoma(group II) and 35 patients of nodular goiter(group II ) respectively. RESULTS The expression of HIF-1 alpha in group I (75. 3%) was higher than that in group I (18. 8% ) and in group III (14. 3%) ( P <0. 01). The similar results were also observed about VEGF and VEGF-C. The positive rate of VEGF and VEGF-C (72. 6% and 65. 8%) in group I were markedly increased, compared with that in group II (18. 8% and 15. 6%, P<0. 01) or III (20. 0% and 11. 4%, P <0. 01) . In carcinoma patients with lymph node metastasis, the higher expressions of HIF-1a,VEGF and VEGF-C were observed as compared with those without metastasis( P <0. 05,respectively). VEGF and VEGF-C expression had a positive correlation with HIF-1 alpha ( P <0. 05). CONCLUSIONS In papillary thyroid carcinoma, HIF-1 alpha, VEGF and VEGF-C expression are significantly increased. Furthermore,VEGF and VEGF-C expression may be regulated by HIF-1 alpha, involving in the process of cancer cell spreading to lymph nodes.