Influence of curing age on compressive strength, air permeability and water absorptivity of phosphoaluminate cement concrete(PALC) was investigated. The phase composition and morphology of hydration products, electrical properties, pore structure and distribution of concrete were analyzed by various instruments. In addition, the hydration heat test and the cause for early high strength of PAC were investigated as well introduced to test the hydration heat and explain the cause for early high strength of PAC. The results show that the effect of curing age on the apparent performance and micro structure of the concrete is great, and they are related closely. With age, the compressive strength becomes higher, air permeability and absorptivity of concrete decrease. The corresponding fractal dimension of the pore and the micro structure are changed as well. The reason for that is that the more hydration products are generated and the porosity of the concrete is reduced. Furthermore, the properties of phosphoaluminate cement concrete are better than that of Portland cement because of different hydration products and mechanism.