Tapioca starch extracted from the cassava root is one of the most important carbohydrate food sources in many regions of the tropics.Due to the abundance and ease of extraction,tapioca starch has been one of a few commercially-exploited starches.Tapioca starch was modified by branching enzyme (BE) from Bacillus subtilis 168 and Bacillus stearothermophilus maltogenic amylase (BSMA) and changes of side chain distribution and susceptibility for amylolytic enzymes of the modified starch product were investigated.