Investigations of the influence of various factors on the modulus of elasticity and deformability of different types of lightweight concrete are presented.The results show that the modulus are not constant and decrease with the increase of the level of applied stress. Aggregate proposity and volume fraction effects the modulus of elasticity and the modulus of deformability of concrete. Using different concrete mixes of varying strength, it was confirmed that the the modulus of elasticity and the comprehensive strength of concrete are directly proportioned. The modulus of elasticity per unit strength decreases with the age of concrete. As lightweight concrete is a heterogeneous, multiphase material, the volume fraction and modulus of elasticity of the principal constituents influence the modulus of elasticity of the composite material.