Objective To investigate the diagnosis of Crohn's disease(CD)in Ruijin hospital of School of Medicine of Shanghai Jiaotong University according to the criteria made by World Health Organization(WHO)and Chinese Medical Association.Methods The consecutive patients with CD diagnosed in Ruijin hospital between 1998 and 2007 were retrospectively analyzed.The clinical manifestation.endoscopic,radiologic and pathologic findings of all patients were re-evaluated accordingto the diagnostic criteria of CD proposed by WHO and Chinese Medical Association in 2007.The diagnostic level of CD was assessed.Results Only 5 and 10 patients were confirmed to be well consistent with the criteria of WHO and Chinese Medical Association,respectively.Two hundred and thirty-six patients were confirmed as suspected diagnosis to the criteria of Chinese Medical Association and 20 patients to WHO.The level of endoscopic diagnosis was raised,wherease the level ofpathologic diagnosis was decreased in recent years compared with that before 2004.Conclusion The pathologic diagnosis rate of CD is still at a low level.The current diagnostic level of CD is lagging behind the demand of the guidelines.