The determination of isotopic composition in trace amount has become one of the major directions of development of isotopic measurements. A laser extraction system has been assembled successfully and combined with MAT253 mass spectrometer to form a laser analytical system in this study. And the method of analyzing oxygen isotope of silicates and oxides was development. Research objects are some typical eutexia and refractory minerals, including international standard material NBS28, quartz glass, garnet, zircon and olivine, focusing on the homogeneity and variation of oxygen isotopic composition in trace amount. The analytical precision of particle samples is ±0.22‰, and its oxygen contents for analysis are reduced to 8μMol. The analytical precision of insitu quartz glass is ±0.35‰, and its oxygen contents for analysis are reduced to 7μMol. With this method, we can analyze very small amounts of materials with high spatial resolution, and it is also characterized by fast analytical rate and high melt temperature, especially for refractory minerals. The method can be used to investigate oxygen isotope zonation, trace amount variations on oxygen isotopic composition and oxygen isotope geochemistry in single mineral, and shows great applications about natural minerals, rocks and mantle inclusions forming conditions and the origin.