Abstract: Objective To improve the understanding of primary sclerotic cholangitis (PSC) and reduce its misdiagnosis rate by studying its clinical characteristics. Methods Clinical characteristics, laboratory testing, ultrasound imaging, histopathology and treatment of 26 PSC patients (16 males and 10 females) aged 35-60 (42.5±6.8) years admitted to our hospital from 2006 to 2011 were retrospectively analyzed. Results The main manifestations were jaundice (80.8%), fatigue (73.1%), and anorexia (69.2%) complicated by cutaneous puritus (34.6%), fever (46.2%), gagesucht (26.9%), and splenomegaly (19.2%). Laboratory tests showed that the serum levels of total bilirubin, alkaline phosphatase, gamma glutamyltranspeptidase, alanine aminotransferase and aspartate aminotransferase were slightly increased. Immunoassay showed a higher IgG level in 18 patients, anti-neutrophil cytoplasmic antibody in 9 patients, anti-nuclear antibody in 4 patients, and anti-smooth muscle antibody in 1 patient. Cholangiography revealed multifocal stricture and segmental dilatation in 24 patients (92.3%). Ultrasonography demonstrated thickened wall, enhanced echo, segmental dilation and stenosis of bile duct with different degrees of cholestasis in 21 patients (80.7%). Colonoscopy displayed ulcerative colitis in 8 patients (30.8%). Liver biopsy discovered proliferation of fbrous tissue and infltration of infammatory cells. Of the 26 patients, 21 had signifcant improvements of their symptoms and signs, 2 with autoimmune pancreatitis and 3 with cirrhosis had a poor outcome after treated with ursodexycholic acid and/or stent implantation. Conclusion PSC is an injury of bile duct due to systemic autoimmune diseases and usually accompanied by other immune diseases. Its diagnosis can be established according to its clinical features, biochemical test, immunological test, medical imaging and histopathology when other diseases are excluded. The main therapy for PSC is expectant and support treatment.