Objective: To investigate the application value of nano-carbon tracing in lymph node dissection and protection of parathyroids during endoscopic surgery for thyroid carcinoma. Methods: One hundred and twenty-six patients with papillary thyroid carcinoma undergoing endoscopic thyroid surgery during January 2013 to January 2015 in Xiangya Hospital, Central South University were enrolled and randomly assigned to control group (40 cases), methylene blue group (41 cases) and carbon nanoparticle group (45 cases). Patients in control group underwent regular operation, while those in the other two groups were injected with corresponding tracer during operation. The number of retrieved lymph nodes and metastatic lymph nodes and inadvertent parathyroidectomy in each group were calculated. Further, both stained and unstained lymph node specimens from methylene blue group and carbon nanoparticle group were pathologically examined. Results: No anaphylactic reactions occured in the two groups of patients receiving tracer injection. The number of detected lymph nodes in carbon nanoparticle group was significantly higher than that in either control group (t=5.164, P<0.05) or methylene blue group (t=4.763, P<0.05). Further, the detection rate of tiny lymph nodes (<2 mm) in carbon nanoparticle group was significantly higher than that in methylene blue group (29.3% vs. 13.2%; χ2=18.231, P<0.05), while no tiny lymph nodes were detected in control group. There was no significant difference in rate of lymph node metastases among the three groups (P>0.05), but the staining rate of metastatic lymph nodes in carbon nanoparticle group was significantly higher than that in methylene blue group (92.2% vs. 78.8%; χ2=5.605, P<0.05). Eighteen inadvertently resected parathyroid glands were found in control group, while no inadvertent removal of parathyroid glands occurred in both methylene blue and carbon nanoparticle groups. Conclusion: Nano-carbon is superior to methylene blue in targeting lymph nodes and the tracing effect may help surgeons conduct a more thorough lymph node dissection. Meanwhile, its application can effectively avoid inadvertent parathyroidectomy. So, its clinical application is recommended.