Abstract: Objective To investigate the expression of Cyclin D1 and phosphatase and tensin homolog deleted on chromosome ten （PTEN） in patients with papillary thyroid carcinoma （PTC）， and their clinical significance. Methods From March 2013 to December 2014， 70 cases of PTC and paired adjacent normal tissues were enrolled. The expression of PTEN and Cyclin D1 in above tissues was detected by immunohistochemical EnVision twostep method. The correlation of Cyclin D1 and PTEN， as well as the relationship of them with clinicopathological features were analyzed. Results The positive rate of Cyclin D1 was 77.1％ （54／70） in PTC tissues， higher than 12.9％ （9／70） of adjacent normal tissues with statistical significance （P＜0.001）. The positive rate of PTEN was 21.4％（15／70）in PTC tissues， lower than 81.4％ （57／70） of adjacent normal tissues with statistical sgnificance（P＜0.001）. The expression of Cyclin D1 was related with lymph node metastasis and clinical staging（P＜0.05）， but not with age， gender and the size of tumor（P＞0.05）. The expression of PTEN was associated with gender， lymph node metastasis and clinical staging（P＜0.05）， but not with age and the size of tumor（P＞0.05）. Cyclin D1 was not correlated with PTEN （r=0.105， P=0.386）. Conclusion Cyclin D1 is overexpressed in PTC tissues， while PTEN is lower expressed. The two proteins are both related with lymph node metastasis and clinical staging. Cyclin D1 and PTEN may play a role in the occurrence and development of PTC.