Abstract： Objective:To compare the effect of nanocarbon tracer technology vs contrast-enhanced ultrasonography on short-term outcomes of patients with thyroid cancer undergoing surgery.Methods:A total of 80 patients with thyroid cancer treated in our hospital between September 2019 and September 2020 were recruited and randomly divided into the control group and the study group ( n=40 each) . All patients underwent surgical treatment for thyroid cancer, assisted by nano-carbon tracer technology (control group) or contrast-enhanced ultrasonography (study group) for lymph node localization. The operation time, intraoperative blood loss, volume of postoperative incision drainage, length of postoperative hospital stay, number of lymph nodes dissected, numbers of metastatic patients, patients with postoperative hoarseness and patients with inadvertant parathyroidectomy, changes in serum Ca 2+ and parathyroid hormone (PTH) levels at 1, 3, 5, 7 days and at 3 months after surgery, and symptoms of parathyroid injury at 3 months after surgery, were compared between the two groups. Results:The mean number of lymph nodes dissected was smaller in the study group (8.14±2.13) than that in the control group (9.37±2.24) , but the ratio of positive lymph node dissection was higher in the control group (97.50%) than that in the control group (82.50%) (both P<0.05) . There were no significant differences between the two groups in operation time (117.93 ±17.46 vs 115.34±15.68 min) , intraoperative blood loss (47.33±10.46 v 46.74±12.63 mL) , volume of postoperative incision drainage (34.77±6.57 vs 36.32±5.89 mL) , length of postoperative hospital stay (6.76±1.54 vs 7.15 ±1.62 d) , proportions of metastatic patients (17.50% vs 15.00%) , patients with postoperative hoarseness (25.00% vs 30.00%) and patients with inadvertent parathyroidectomy (7.50% vs 15.00%) (all P>0.05) . The serum Ca 2+ and PTH levels in either group were lower than baseline at 1, 3, and 7 d after surgery ( P<0.05) . There was no significant difference in serum Ca 2+ or PTH level at 3 months after surgery compared with baseline in either group, nor at any time points between the two groups ( P>0.05) . There was no statistically significant difference in incidence of tetany, limb numbness, muscle spasm and limb paresthesia between the two groups after surgery ( P>0.05) . Conclusion:Contrast-enhanced ultrasonography is more favorable than nano-carbon tracer technology technique in ratio of positive lymph node dissection, but the two methods are equivalently useful in terms of less reduction of serum Ca 2+ and PTH levels after surgery, fewer symptoms of parathyroid injury, and protection of thyroid functions.