In order to improve the interfacial bonding properties of synthetic fiber cement matrix, a series of modified fibers were prepared by sol gel chemical deposition of nano silica. The effect of chemical deposition time on modification efficiency and the distribution of nano particles on the fiber surface were observed with energy dispersive spectrometer(EDS) and scanning electron microscope(SEM). Single fiber pull out behavior and plastic crack resistance experiments were carried out to confirm the advantage of modified fiber. The results demonstrate that the proper chemical deposition time is 60min for polypropylene(PP) fiber and the mean diameter of nano silica particles is about 300 nm. As for hydrophilic property, the distribution morphology of nano silica on polyvinyl alcohol(PVA) fiber surface is obviously different. The interfacial bond strength of modified fiber matrix is improved significantly from the pull out behavior curves, therefore, all the modified fibers have excellent crack resistance property. The interfacial property of fiber matrix is improved because of hydration activity of silica. The hydration products act as chemical combination and physical anchors during pull out and crack resistance.