PURPOSE: To provide a producing method of lightweight cellular concrete capable of producing a lightweight cellular concrete having excellent tobermolite crystallinity and excellent in durability.

CONSTITUTION: In the producing method of lightweight cellular concrete by using a siliceous raw material composed of silica rock or quartz sand, a calcareous raw material composed of cement and lime and water as the main raw materials, mixed material obtained by mixing slaked lime with 0.1-1wt.% silica raw material per the slaked lime and dry grinding is used as one part or all part of the calcareous raw material.