Tricalcium silicate based binder provides a simple matrix with only two hydration products: calcium silicate hydrate (C-S-H) and calcium hydroxide (CH). This feature is attractive to researchers who like to more accurately assess the Portland cement-based binders' phases separately. However, different purity than ordinary Portland cement clinkers could alter the properties of hydrated gels. This paper compared the nanomechanical and chemical properties of synthesized tricalcium silicate (C3S) paste with ordinary Portland cement (OPC) paste using nanoindentation and energy dispersive X-ray spectroscopy (EDS) method. The deconvolution statistical methodwas used to further analyze the nanoindentation test results and compare with theEDSchemical mapping. Results indicated that C3S paste has a stiffer and more homogeneous (as the C3S paste consists only high-density C-S-H and CH) micromechanical properties than OPC although the calcium to silica ratio of C3S paste is in the range of OPC binders. In addition, the C3S paste seems to have lower porosity than OPC paste due to the lack of observation of the low elastic moduli.