InAsxP1-x (0 less than or equal tox less than or equal to1) nanocrystals with a size of 4-5 nm embedded in SiO2 thin films were prepared by the radio frequency magnetron co-sputtering technique. X-Ray diffraction and Raman spectra suggest the existence of InAsxP1-x nanocrystals in SiO2 matrices. It was found that the frequencies of transverse-optical (TO) and longitudinal-optical (LO) phonons depended on the composition of the InAsxP1-x nanocrystals. The optical absorption band edges of the InAsxP1-x-SiO2 composite films shift to lower energy with increasing the As content. The optical band gaps reveal a marked blue shift with respect to their bulk quantum confinement effect occurs in material. The marked blue shift of optical absorption edge indicates that the strong InAsxP1-x-SiO2 composite films.