We have previously developed biodegradable β-tricalcium phosphate (β-TCP) cement based on the chelate-setting mechanism of inositol phosphate (IP6). The β-TCP cement powder for the cement fabrication was prepared via a novel powder preparation process, in which the starting β-TCP powders were prepared by simultaneous ball-milling and surface-modification in the IP6 solution. In the present study, the novel powder preparation process was applied to an α-TCP powder, and effect of milling time and beads size for ball-milling on the material properties of the a-TCP powders was investigated. The α-TCP powder ball-milled in 1000 ppm IP6 solution for 4 h with 2 mm-diameter beads was composed of single phase α-TCP with the smallest particle size of 2.2 um. Dissolution of 4 h-milled α-TCP powder was approximately twice higher than that of starting α-TCP powder before ball-milling. The α-TCP powder with high dissolution property prepared via the novel powder preparation process is potential candidate for fabrication of the chelate-setting cement.