Abstract. Starch is an economical excipient that is used in oral dosage form. It has poor compressibility and flowability. Pregelatinization and co-process as a physical modification technique have been conducted widely; nevertheless, the single modification shows a limitation. This study aims to assess and characterize the starch result of the modification of various tubers by a combination of modification methods. The starches from various tubers were extracted by sedimentation. Starch pregelatinization was conducted by manufacturing a starch suspension and was heated at 55oC for 70 minutes, and then it was mixed using concentrations HPMC k15 of 2, 3, and 4% (w/w) of the starch weight. The evaluations that were conducted are general identification, amylose concentration, physical properties, and physicochemical identification. The obtained starch of the extraction was 10-18% of the fresh tubers, with the concentration of amylose around 21-37%. The shape and particle size of the starch affected the amylose concentration. The starch modification showed an improvement of the granules physical properties by addition of HPMC. The amylose concentration of yam starch was 37.60% and showed the optimum modification result in the addition of HPMC 4%. There were no changes in the physicochemical properties of the result of IR and X-ray diffraction analysis. The melting point of yam starch-HPMC 4% was 151.24oC with reduction of the maximum weight at 328.52oC. This study indicated that the yam starch has the highest amylose concentration with optimum granules result of the modification in addition of HPMC 4% that could be used as an alternative excipient.