Nano Silica (Nice) has a wide range of applications because of its unique physical and Chemical properties. The silica nanoparticles were prepared by the sol-gel process Different values ​​of the gel (2, 4, 6, 8 and 9). Phase analysis, particle Size / morphology and specific area of ​​prepared nano silica (Using different techniques such as x-ray spectroscopy (Zircon), Fourier transform infrared spectrometer (FRET), electron transmission Microscope (TEM), Natural Gas adsorption for Bronor, Emmett and ATM (House) Method, atomic force microscope (AFM) and electron microscopy scanner (SIM) With scattered energy X-ray analytical (ADAX). Interaction is ready Nano has studied silica by investigating the mechanism of reaction with calcium Hydroxide (Ca (Oh) 2). Nano silica with calcium hydroxide mixed by different 10%, 20%, 30% and 50% using water to the ratio of calcium hydroxide from 0.35, the relative humidity mixture was kept 100% for 7 days. After treatment for 7 The days of reaction mechanisms have been investigated through the differential scan rate (DSC), X-ray diffraction (Zerid) and electron microscopy (SIM). It was It has been found that nano silica consumes calcium hydroxide (CH) Silicate Hydrate (KSH) (the strength of the phase responsible in cement hardening). % In consumer consumption increases with the proportion of silica nano. The Results showed that nano silica prepared amorphous no matter how pH values. The particle size ranges from about 12 nm up to 80nm and has a high specific Prepared, prepared, prepared, prepared, prepared, prepared, prepared, prepared, prepared...