Abstract: Objective:To investigate the clinical and pathological characteristics of papillary thyroid carcinoma(PTC) complicated with hashimoto thyroiditis(HT).Methods:Forty-three patients with PTC complicated with HT and 45 patients with PTC were divided into the observation and control group,respectively.The clinical and pathological characteristics between two groups were compared.Results:The thyroid enlargement and neck compression symptoms in observation group were more than those in control group(P<0.05).The differences of the goiter,neck pain,hoarseness and swallowing difficulty between two groups were not statistically significant(P>0.05).The proportion of female and less than or equal to 44 years old patients in observation group were significantly higher than those in control group(P<0.05).The differences of lymph node metastasis,clinical stage,tumor type,number of cancer lesion and prognosis between two groups were statistically significant(P<0.05).Conclusions:Compared with the PTC patients,the thyroid enlargement and neck compression symptom in PTC complicated with HT patients are more common.The young middle-aged people female,less lymph node metastasis,earlier clinical stage and better prognosis are the main clinical characteristics.