Factors affecting granulatabilities in the tumbling melt granulation (TMG) method for the preparation of spherical beads without using any solvent were investigated. Beads of ten kinds of non-meltable materials were prepared using hydrogenated rape oil (HRO) as binder by changing the mixing ratio of the meltable material (X M ), and the recovery percent (Rec%) and yield percent (Ysc%) of the non-agglomerated core beads were evaluated. In all the powders, both Rec% and Ysc% were excellent with choice of the optimum mixing ratio (X op ), suggesting the great advantage of this method. The values of liquid saturation of the coated layer (Φ) at X op were calculated as around 0.4 in bisbentiamine, cornstarch, lactose, talc, titanium dioxide, and zinc oxide; and around 0.6 in the four cellulose derivatives. The high values in cellulose derivatives could be due to the penetration of the meltable materials into these powders. Thus, X op seemed to be determined in ordinary powders by choosing X M which would give the Φ value of 0.4. The granulatability became worse as the viscosity of the meltable material increased, but the wettability evaluated by the liquid penetration method did not have much effect on the granulatability, in contrast with the wet granulation. From these results, the difference in the granulating mechanism between TMG and wet granulation was discussed.