Silica nanoparticles are of promising applications in many current and emerging areas of technology because of their nature advantages. This review is devoted to the progress made in the last decade in synthesis and green chemistry application of silica nanoparticles. We present a comprehensive overview of synthetic strategies for silica nanoparticles. The ability to control the particle size and distribution was found highly dependent on mixing modes of the reactants and drying techniques. Silica nanoparticles with good dispersion, different morphology and tuning pore sizes are successfully synthesized by means of the sol-gel method. Green chemistry application of synthesis of silica nanoparticle has drawn much attention, due to the increased demand for new materials with improved thermal, mechanical, physical, optical and chemical properties. And this application of silica nanoparticles in materials chemistry procedures to synthesize highly efficient silica nanoparticles and films that can be used for the treatment and disinfection of water and wastewater, and highly sensitive devices for the development of new type of sensors are mostly described. This paper is written by emphasizing on the synthesis of silica nanoparticle, characterization on size-dependent properties for the preparation of homogeneous nanocomposites, generally by sol-gel technique, and show great promise for use in variety of green chemistry applications where special structure and properties are required.