The influence of polycarboxylic-type admixture on the strength of autoclaved aerated concrete(AAC) was investigated. The flexural strength and compressive strength of AAC with polycarboxylic admixture(PA) were tested. The microstructure of AAC reinforced by PA was analyzed using scanning electron microscopic(SEM) methods. The crystal structure analysis of AAC with PA was also carried out using X-ray diffraction(XRD). The results showed that the compressive strength and flexural strength of AAC were increased by 43.9% and 42.8%, respectively, when 1.5wt% of PA was mixed. In addition, the dosage of admixture influenced the reinforcing effect. Admixture affected pore structure and surface characteristic of the products in autoclaved curing process and improved the formation of high crystallite tobermorite which led to the enhancement of the compressive and flexural strength of AAC. The influence of polycarboxylic-type admixture on the strength of autoclaved aerated concrete(AAC) was investigated. The flexural strength and compressive strength of AAC with polycarboxylic admixture(PA) were tested. The microstructure of AAC reinforced by PA was analyzed using scanning electron microscopic (SEM) methods. The crystal structure analysis of AAC with PA was also carried out using X-ray diffraction (XRD). The results showed that the compressive strength and flexural strength of AAC were increased by 43.9% and 42.8%, respectively, when In addition, the dosage of affected properties of the reinforcing effect And flexural strength of AAC.