To further understand the influence of climate environment on the microstructure of concrete materials in northwestern China, the microstructure characteristics of concrete under different temperature and humidity curing conditions were investigated by a nano-indentation technology. The results show that the lack of curing temperature and humidity leads to the increase of capillary pores and low-density calcium silicate hydrate (C-S-H) gel content in cement mortar. The indentation modulus and hardness of concrete interfacial transition zone (ITZ) under different curing conditions were statistically analyzed. It is indicated that the average thickness of concrete ITZ is increased by 5 μm and 10 μm when the curing conditions are 10 ℃-70% relative humidity (RH) and 3 ℃-50% RH, respectively, compared with that the curing condition is 20 ℃-95% RH.