Nanomaterial concrete is new generation concrete formed of materials of the grain size of nanoscale. The composition of nanomaterial concrete consists of cement, nanosilica grain of the size of 10 nm - 140 nm, fine sand of the grain size of 0.125 mm - 0.50 mm, quartz powder of the size of 16 µm - 90 µm, coarse aggregate of a maximum grain size of 15 mm, and superplastisizer. Nanomaterials have properties or functions different from similar materials of large size. Nanomaterials have a larger value of the ratio between surface area and volume than other similar particles in larger size, making the nanomaterials more reactive. This paper presents the influence of nanosilica as a partial substitution of cement in concrete. The presence of nanosilica in concrete is intended to accommodate the byproduct of the cement hydration production in the form of free hydroxide calcium. Nanosilica will react with C3S and C2S in the cement and produce CSH-2 that will form a strong and solid bond of gel. The results showed that the addition of nanosilica as cement partial substitute material could improve the mechanical behavior of the concrete