Objective To study the morphological character of blood-spleen barrier in patients with hypersplenism,and to discuss the relevance and pathogenesis of hypersplenism.Methods The spleens of 33 patients with cirrhosis with portal hypertension were collected as the experimental group,and 20 patients with traumatic spleen as the matched group.Five pieces of tissues in each spleen were sampled.The samples were made into pathological sections,stained with H.E.and examined microscopically for the total number of germinal centers (GC).The data of patients before operation were collected which included:blood routine (count of RBC,WBC,PLT and HB) and splenic weight.The correlation of blood routine values and sum of GC was studied using relative linear analysis.Results In the experimental group:The blood routine values were remarkably lower,splenic weight (average 764.2 g) and the quantity of the germinal center (average 8817/case) were higher.There was a reverse relationship between the total quantity of germinal centers and the PLT.There was a close relationship between the quantity of germinal center and the extent of the hypersplenism,i.e.the lower the preoperative platelet number,the greater the total number of germinal center; the heavier the splenic weight,the greater the number of germinal center.Conclusions The total number of germinal center increased dramatically in patients with cirrhosis with portal hypertension.The change is accompanied by changes in morphology of the germinal centers and dysfunction in blood-spleen barrier.It is likely that hypersplenism develops on the basis of dysfunction of blood-spleen barrier.