The objective of this study is determining the mechanical property of light and strong preformed structural lightweight foamed concrete using the mineral foam agent. Also the structural lightweight foamed concrete has superior property of insulation and lightweight because it has many inner. So, the structural lightweight foamed concrete used to need property of insulation. Experiment was done to examine mechanical and insulation properties of the specimen according to the variation of structural lightweight foamed concrete is superior than ordinary portland concrete. Moreover, it is known that the concrete has enough for member when foaming agent proportion is 0.4~5%.