Abstract: Objective: To explore the relationship between thyroid function alteration, cholesterol levels and the pathogenesis of nodular goiter accompanied with gallstone. Methods: One hundred and twenty nodular goiter patients accompanied with gallstone,128 simple nodular goiter patients and 50 healthy control cases were collected with ultrasound examination and postoperative pathological diagnosis. The peripheral venous blood of these cases in the three groups were collected and serum thyroid stimulating hormone(TSH), total triiodothyronine(TT₃),total tetraiodothyronine(TT₄),total cholesterol(TC),high-density lipoprotein cholesterol(HDL-C),lowdensity lipoprotein cholesterol(LDL-C) and total bile acid(TBA) levels were measured by electrochemiluminescence method,and the changes of thyroid function and cholesterol levels were observed among the three groups. Results: The serum TT₃ levels in nodular goiter accompanied with gallstone group and the simple nodular goiter group were significantly lower than in control group(P < 0.01),and TSH levels in the former two groups were significantly higher than in control group(P < 0.01). There were no significant difference of TT₄ levels among the three groups(P > 0.05). Accordingly,TC and LDL-C levels in nodular goiter accompanied with gallstone group were significantly higher,while TBA levels were significantly lower than in simple nodular goiter group and control group(P < 0.01). The levels of TC and LDL-C had no statistical difference between simple nodular goiter group and control group(P > 0.05). The HDLC level in nodular goiter accompanied with gallstone group was higher than in simple nodular goiter group. Conclusions: The originating etiologic factor of nodular goiter accompanied with gallstone may be that the decreased TT₃ induced progressive subclinical hypothyroidism. Exogenous L-thyroxine sodium salt supplement maybe prevent the pathogenesis of nodular goiter accompanied with gallstone.