This study was carried out to evaluate the effect of different gamma radiation doses to decontamination of micro-organisms present in Guar gum powder. As well as to study the effect of radiation on the chemical and physical properties of the carbohydrate components of the gum's material. Two types of samples were used in this study (powder and liquid). All samples were collected from commercially available guar gum (GG), which were obtained from the company (Sudanese guar gum.ltd). Samples putted in polyethylene tightly closed container, then irradiated by applying different doses (2.5, 5,...