The complex behavior of concrete is largely related to the mechanical response of calcium silicate hydrate (C-S-H) gel. During the past two decades, a great deal of efforts has been devoted to the structure of C-S-H at the nanoscale level, including both experiment investigation and molecular simulation. The smallest C-S-H unit has a layered crystal structure at atomic scale, with a lamella thickness in the nm range. And moreover, ordered stacks of up to several tens or even hundreds of nano-lamellae have been observed experimentally. The key features of structure and morphology is remarkably the ubiquitous presence of an orientational order. Now we focus on the physical understanding on such orientational ordered C-S-H structures at mesoscale. In respect that there exists a high nematic order in the stacking C-S-H of nano-lamellae, by introducing some physical parameters, such as the magnitude of nematic order of the nano-lamellae, we try to predict the mechanical properties of the crystalline in terms of its micro-structure.