Objective To investigate the genetic susceptibility to inflammatory bowel disease in China.Methods The pedigree of 5 probands with inflammatory bowel disease (2 with Crohn's disease and 3 with ulcerative colitis) were analyzed including familial history,clinical features,radiographic,endoscopic and pathological findings.A detailed family pedigree and information of the whereabouts of each relative were obtained.Results Crohn's disease was found in 2 families,each with two affected patients (two brothers or mother and a child).Ulcerative colitis was i'ound in 3 families,each with two or more affected patients (an elder sister and younger brother in the first family,mother and a child in the second family and grandparent and 2 grandchildren in the third family ).First-degree relatives were susceptibility to inflammatory bowel disease and siblings were affected more frequently.The member of the later generation was younger at diagnosis than the preceding generation. Offsprings had an earlier onset and more severe than affected parents. A high concordance for type and localization was found between males and females.Conclusions The patients with inflammatory bowel disease have genetic susceptibility and a few member may affect.It may result from multigene or autosomal recessive inheritance.