Objective To analyzed the expression of serum Interleukin-2(IL-2),Interleukin 12 P70(IL-12P70),in-terleukin-10(IL-10)and interleukin-17(IL-17)in Hashimoto's thyroiditis carcinoma(HT)and papillary thyroid carci-noma(PTC),to investigate the role of 4 kinds of cytokines in HT and PTC.Methods Thirty patients with Hashimoto's thyroiditis,35 patients with papillary thyroid carcinoma,and thirty healthy individuals were selected from Tongde Hos-pital of Zhejiang Province from July 2022 to June 2023.They were divided into HT group,PTC group,and healthy con-trol group.The serum levels of IL-2,IL-12P70,IL-10,and IL-17 were detected by flow cytometry.Results Compared with the healthy control group,the serum levels of IL-2,IL-12P70,and IL-17 were significantly higher in both the PTC and HT groups(P<0.05).Compared with the HT group,the serum level of IL-10 was significantly increased in the PTC group[(9.46±2.22)pg/mL vs.(7.44±1.97)pg/mL,P<0.05].In the HT group,thyroid peroxidase antibody(TPOAb)levels were negatively correlated with the level of IL-10 and positively correlated with the level of IL-17(P<0.05).The level of thyroglobulin antibody(TgAb)was negatively correlated with the level of IL-10(P<0.05).The levels of IL-2,IL-12P70,IL-10,and IL-17 in thyroid tumor patients showed no significant differences after total thyroid-ectomy or thyroid gland with isthmus resection(P>0.05).Conclusion The serum levels of IL-2,IL-12P70,and IL-17 elevated in PTC and HT patients,while the serum levels of IL-10 decreased in HT patients and correlated with TPOAb and TgAb levels.There were no significant changes in the levels of these cytokines after total thyroidectomy or thyroid gland with isthmus resection in patients with PTC.