Abstract: Objective:To investigate the clinical effects of nano-carbon suspension in cleaning the central lymph nodes in papillary thyroid carcinoma.Methods:Forty patients with papillary thyroid carcinoma were randomly divided into the observation group and control group by the random number table method(20 cases each group).The observation group and control group were treated with and without nano-carbon suspension,respectively.The lymph node dissection condition and parathyroid hormone level between two groups were compared.Results:Two hundred and twenty-one lymph nodes were dissected in observation group,and the staining rate of lymph node in observation group was 96.67%.One hundred and sixty-five lymph nodes were dissected in control group.The ratio of positive lymph node,ratio of lymph node with diameter <0.3 cm,average detection rate of lymph node in observation group were higher than those in control group(P<0.01).There was no statistical significance in the preoperative serum levels of calcium and parathyroid hormone between two groups(P>0.05).After 1 day of operation,the serum levels of parathyroid hormone in two groups and calcium level in control group decreased compared with before operation(P<0.05 to P<0.01),and the serum levels of calcium and parathyroid hormone in observation group were significantly higher than those in control group(P<0.01).Conclusions:The application of nano-carbon suspension in cleaning the central lymph node of papillary thyroid carcinoma can improve the completeness of cleaning,protect the parathyroid gland function,which is worthy of promotion.