Concrete specimens were cured in the cycling surroundings of 0-60℃ of temperature and 30-50% of RH. The mechanical properties, microhardness, XRD and SEM were tested on the concrete. Compared to samples that cured in standard condition, the early strength of the specimens cured with cycling temperature-humidity surroundings was slightly higher, but it became lower than the latter 3 days after. Moreover, the difference was gradually increased with time. The results of XRD and SEM show that a low relative humidity and fluctuant temperature-humidity surrounding can cause a low degree of hydration, the wider ITZ thickness, and affect the mechanical properties of concrete.