The calcium-silicate-hydrate(C-S-H) existing in cement-based materials has been focused on for a long time, however, the nanometer-scale properties are rarely concerned, because of its complicated structure. In this paper we study the nanomechanical properties of C-S-H by nanoindentation measurement, particular attention is paid to the pastes cured for 2 days and 28 days, respectively, both at 20°C and 60°C. The results demonstrate in all cases the existence of two types of C-S-H with low stiffness and high stiffness. Also, the two types of C-S-H are of different characteristic modulus. The average modulus of each C-S-H is almost the same for all pastes tested, indicating that the heat curing process does not change the intrinsic mechanical properties of the C-S-H. However, the volumetric proportion of two types of CSH is changed at 60°C compared to that at 20°C at the early age.