Objective To investigate the clinical features of patients with immune-mediated necrotizing myopathy （IMNM） overlap syndrome.Methods A total of 15 patients with overlap syndrome who were diagnosed in Tongji Hospital from 2011 to 2020 were enrolled， and according to the type of connective tissue disease overlapped， they were divided into IMNM- Sjogren’s syndrome （SS） group with 10 patients， IMNM-rheumatoid arthritis （RA） group with 4 patients， and IMNM-systemic lupus erythematosus （SLE） group with 1 patient. The three groups were analyzed in terms of clinical manifestation， laboratory examination， treatment， and prognosis.Results The IMNM-SS group had a relatively high proportion of female patients and the highest serum creatine kinase level of 3129±4719 u/L among the three groups. The IMNM-RA group had a mean course of disease of 3.7±1.7 months， which was the shortest among the three groups. The IMNM-SLE group had a mean age of onset of 23 years， which was the youngest among the three groups. The IMNM-SS and IMNM-RA groups had a relatively high proportion of patients with interstitial lung disease or cardiac involvement and the highest proportion of the patients with the expression of anti-SRP and anti-SS-A/Ro-52 antibodies among serum myositis antibodies. Most patients in the three groups received glucocorticoid combined with immunosuppressant， accounting for 80% in the IMNM-SS group， 75% in the IMNM-RA group， and 100% in the IMNM-SLE group， and 47.6% of these patients were treated with glucocorticoids combined with tacrolimus. Of all patients， 2 patients （13.3%） basically returned to normal and 12 （80%） had achieved marked improvement.Conclusions There is a lack of marked specific clinical symptoms for different types of overlap syndrome. IMNM-SS and IMNM-RA tend to have a high proportion of patients with cardiac and/or pulmonary injury， and it is recommended to perform heart and lung examinations as early as possible in clinical practice. Most patients can achieve the improvement in clinical symtomps and have good prognosis after the treatment with glucocorticoid and immunosuppressant.