Flyash blocks made of autoclaved aerated concrete (AAC) are lightweight employed quickly in high-rise structures. One of the sustainable materials is the AAC Block, which is made from fly ash from industrial waste. AAC block masonry in fills contribute to a structure's low weight, thermal conductivity, and speed of construction. To increase the effectiveness of the AAC block masonry, material level research is required. The literatures lack a awareness of the material level of behaviour of AAC block construction. In order to comprehend the compressive stress-strain behaviour of AAC Block masonry and its components, experimental study is described in this work. Compression testing is used to determine how well AAC block masonry responds to weak and strong mortar.