Abstract: Crohn's disease (CD) is a chronic autoimmue disease with unkown pathogenesis. In China and other area of Asia, the incidence of CD is increasing rapidly. Due to delay in diagnosis, most CD patients have intestinal stenosis, perforation and other complications as diagnosis, which is one of the main reasons for the poor prognosis of CD. At present, the research focus on CD diagnosis and treatment is how to improve the clinical understanding of the natural course of CD, especially in the early stage, so as to improve the early diagnosis rate, seize the opportunity for its treatment and carry out effective clinical intervention in time. By summarizing the researches on the early diagnosis of CD, this article aims to provide evidences for the early diagnosis and treatment of CD.