Abstract: This article made a research on method of extracting dietary fibre from wheat bran, the condition of extracting,its chemical property,and its chemical composition .At same time we performed some test on its poisonous patholohy index :Acute poisonousness test and ratmarrow cell chromosome distortion test. The conclusions are:The process of extracting is feasible The LD50 by going through rat mouth indicated that the actual situation is nonpoisonous;The result of chromosome distortion test did not show its action on causing mammal cell division test (MI) did not show its action on causing mammal cell mutation. Cell division indexation test (MI ) did not show poisoning on marrow cell.

Key words:  , Wheat bran； Extracting； Dietary fibre； Hemicllulose；