Objective: To investigate the application value of carbon nanoparticle tracer in radical neck dissection for thyroid cancer. Methods: Eighty patients with thyroid cancer admitted during January 2013 to May 2014 were equally randomized into study group and control group. Patients in study group underwent ipsilateral level VI lymph node dissection according to scope of black-stained lymph nodes after the intrathyroid injection of carbon nanoparticles during operation, while those in control group underwent routine ipsilateral level VI lymph node dissection. The number of dissected lymph nodes and metastatic lymph nodes as well as the incidence of parathyroid injury between the two groups were compared. Results: The total number of dissected lymph nodes was 461 (441 black-stained lymph nodes) in study group, and was 272 in control group; the number of lymph nodes with tumor metastasis was 197 in study group, and 106 in control group, and both above parameters had statistical difference between the two groups (both P<0.05). There was no significant difference between study group and control group in lymphatic metastasis rate (42.73% vs. 38.97%, P>0.05). No parathyroid tissue was found in pathological examination and no postoperative hypocalcemia occurred in study group, while parathyroid tissue was found in 5 cases and postoperative hypocalcemia occurred in 5 cases in control group, however, the incidence of parathyroid injury did not reach statistical significance (P=0.055). Conclusion: Using carbon nanoparticles in radical neck dissection for thyroid cancer can clearly show the level VI lymph nodes, and thereby help in complete lymph node dissection, and meanwhile, it does not stain the parathyroid tissue, so it can avoid the inadvertent dissection of the parathyroid glands.