Objective：TACI is an important receptor of BAFF/APRIL pathway system. To investigate the level of serum soluble TACI （sTACI） in patients with different types of autoimmune thyroid diseases（AITD），to analyze its relationship with thyroid function and autoimmune antibody，and to explore the role of sTACI in AITD. Methods：Patients who were newly diagnosed with Graves disease （GD） and Hashimoto thyroiditis（HT） in our department and healthy people who had physical examination in physical examination center of our hospital were recruited. Venous blood samples were collected and serum was separated. Expression levels of thyroid function and autoimmune antibody were measured by electrochemical immunoluminescence and expression levels of serum sTACI were measured by enzyme linked immunosorbent assay（ELISA）. Results：Age and gender in the GD group and the HT group had no statistical difference when compared with that in the normal control（NC） group（both P>0.05）. The level of serum sTACI in the GD group，the HT group and the NC group were 13.24（10.40-18.60） pg/mL，12.75（11.17-16.14） pg/mL and 13.05（10.30-18.75） pg/mL，respectively. The level of serum sTACI in the GD group and the HT group had no significant difference when compared with that in the NC group（P=0.812，0.873）. The level of serum sTACI had no statistical difference between the GD group and the HT group（P=0.584）. In the GD group，the level of serum sTACI was not correlated with FT4，FT3，TSH，TPOAb，TgAb and TRAb level（all P>0.05）. In the HT group，the level of serum sTACI was not correlated with FT4，FT3，TSH，TPOAb and TgAb level（all P>0.05）. Conclusion：Compared with the NC group，the level of serum sTACI in AITD patients has no significant change and it has no correlation with thyroid function and autoimmune antibody level，suggesting that TACI receptor of BAFF/APRIL pathway system may not play a crucial role in the pathogenesis of AITD.