PURPOSE: To provide fluidity and moisture-proofness to quicklime powder by coating the particle surface of the quicklime powder with a specific material.

CONSTITUTION: Quicklime powder is coated with one or ≥2 kinds of compds. selected from the groups consisting of stearic acid, stearyl alcohol, paraffin, ethylene-vinyl acetate copolymer and polyester. As a result, the hygroscopicity and flocculating property during storage are suppressed and the fluidity during transportation is improved. The reactivity thereof can be recovered easily whenever necessary. In this method, said specific compd. is preferably used in the state of a soln. wherein the compd. is dissolved in a suitable solvent. As the suitable solvent, toluene, n-hexane, etc. may be mentioned, and the amt. of the compd. to be used for coating is normally 0.5W5.0% by wt. of the quicklime powder although the amt. depends on the compd. used. The surface treated quicklime powder obtd. by this method restores the intrinsic activity when heated for 10min at about 400°C, for example.