In Lightweight Aggregate Concrete manufacturing, there is a stratification of lightweight aggregate during construction process, because bulk density of lightweight aggregates is much smaller than that of cement mortar. This paper presents some research results about the effect of air entrainment additive on the properties of lightweight aggregate concrete. When adding air entrainment admixture into lightweight concrete components with the amount of 0.02 – 0.08% by mass of binder, the stratification and bulk density of fresh concrete reduce, and strength of hardened concrete is also significantly reduced. Therefore, this result indicates that we should only use the air entrainment additive in small amounts (less than 0.02% by mass).