Monodisperse,　spherical,　organo-functionalized　silica　particles　were　prepared　by　a　one-pot　method.　Vinyl-silica　and　amine-silica　were　prepared　by　the　hydrolysis　of　tetraethyl　orthosilicate　in　aqueous　alcohol　solutions　with　the　addition　of　vinyl　triethoxysilane　and　3-aminepropyl　triethoxysilane,　respectively,　while　thiol-silica　was　prepared　by　the　hydrolysis　of　3-mercaptopropyl　in　water　without　ethanol.　The　organo-functionalized　silica　particles　were　characterized　by　transmission　electron　microscopy,　scanning　electron　microscopy　and　energy　dispersive　spectrometer.　Organo-silica　particles　had　lower　water　swell　by　introduction　of　organic　groups　on　the　surface　of　silica　particles.　Afterwards,　organo-functionalized　silica　particles　were　dispersed　in　polyurethane　(PU)　to　improve　the　mechanical　properties　of　PU.　The　mechanical　properties　of　PU　films　were　measured　by　universal　testing　machine　and　sclerometer.　The　results　showed　that　the　tensile　strength,　Flexural　strength　and　hardness　of　PU　films　were　obviously　improved　with　the　addition　of　organo-silica　particles.