Objective The aim of the study was to detect circulating differentiated thyroid cancer(DTC) micrometastasis and to investigate the factors influencing their presence in the perioperative thyroidectomy period. Methods DTC micrometastases in the peripheral blood were detected with flow cytometry,and patient clinical and pathological factors were analyzed in 327 DTC patients. Results Circulating blood micrometastases were present in the peripheral circulation at a higher rate 1 week postoperatively than preoperatively and at 4 weeks postoperatively(P < 0.05). The preoperative presence of circulating micrometastasis was associated with the size of the tumor and the presence of lymph node metastasis(P < 0.05),but was not related to the degree of tumor differentiation(P > 0.05). At 4 weeks postoperatively,the presence of circulating micrometastasis was not associated with tumor size or lymph node stage(P > 0.05),but was associated with poorly differentiated tumors(P < 0.05). Conclusion The presence of circulating DTC micrometastases correlates to tumor size,lymph node stage,and operative manipulation. The differentiation degree of the tumors were associated with the persistent presence of micrometastasis in the circulating blood. Objective The aim of the study was to detect circulating differentiated thyroid cancer (DTC) micrometastasis and to investigate the factors influencing their presence in the perioperative thyroidectomy period. Methods DTC micrometastases in the peripheral blood were detected with flow cytometry, and patient clinical and pathological factors were analyzed in 327 DTC patients. Results Circulating blood micrometastases were present in the peripheral circulation at a higher rate of 1 week postoperatively than preoperatively and at 4 weeks postoperatively (P <0.05). The preoperative presence of circulating micrometastasis was associated with the size of the tumor and the presence of lymph node metastasis (P <0.05), but was not related to the degree of tumor differentiation (P> 0.05). At 4 weeks postoperatively, the presence of circulating micrometastasis was not associated with tumor size or lymph node stage (P> 0.05), but was associated with poorly differentiated tumors (P <0.05). Conclusion The p resence of circulating DTC micrometastases correlates to tumor size, lymph node stage, and operative manipulation. The differentiation degree of the tumors were associated with the persistent presence of micrometastasis in the circulating blood.