1.1　Introduction

Autoimmune pancreatitis（AIP）is a relatively rare type of pancreatitis with a hypothesized autoimmune mechanism.It was first described by Sarles et al.（1961）as a subtype of idiopathic chronic pancreatitis（CP）in 1961.AIP was proposed as a clinical entity in 1995（Yoshida et al.1995）.Yoshida et al.（1995）reported that this type of pancreatitis had several unique clinical，serological，and morphological features including increased serum y-globulin or immunoglobulin（Ig）G levels；diffuse enlargement of the pancreas and narrowing of the main pancreatic duct（MPD）；biliary stenosis；good response to steroids；and lymphoplasmacytic sclerosing pancreatitis（LPSP）on histology.Thereafter，extensive research has been conducted in this field over two decades and AIP has been established as a unique disease entity（Kamisawa et al.2013；Hart et al.2015b；Okazaki and Uchida 2015）.In this chapter，we mainly review the diagnosis and management of AIP.(https://www.daowen.com)