Abstract: Objective To explore the diagnosis and treatment of gastrointestinal IgG4-related disease (IgG4-RD) and provide evidence for the differential diagnosis of gastrointestinal diseases. Methods A 53-year-old man with multiple intrahepatic masses and edematous wall thickening of the ascending colon admitted to our hospital in June 2016 underwent several preoperative imaging examinations,and then he received right hemi-colectomy for suspected malignant tumor. Results Gross inspection showed a significant wall thickness in the ascending colon,and the lesion was 8cm in length.Pathological examination demonstrated increased number of plasma cells infiltration and IgG4-positive plasma cells (30/HPF),and elevated IgG4/IgG ratio (>40%).The patient was diagnosed as IgG4-RD. Conclusion Gastrointestinal IgG4-RD appears to be difficult to diagnose before surgical resection because it is rare and similar to malignancy.The measurement of serum IgG4 level,immunohistochemical examination of biopsy specimens and use of several imaging modalities may help us in preoperative diagnosis.However,surgical resection for IgG4-RD is necessary for patients with concerns regarding malignancy or with intractable gastrointestinal obstruction caused by this disease.