The conventional bromine trifloride method and bromine pentaflour ide method are recapitulated.Both methods cant react completely with some high temperature minerals such as high Mg olivine, garnet,kyanite etc.The laser microprobe method is introduced here.It is demonstrated that the laser micro probe method has the short analysis cycle and high precision in contrast to the conventional method. The fractional effects associated with the oxygen yields and oxygen carbondioxide conversion stage are discussed too.Data given by laser microprobe method lately terminated the controversy on the O isotope system of peridotite, the results show that the peridotite minerals may have gotten fractional equilibrium.Meanwhile the laser microprobe is a powerful tool in study sulfur isotope zonation and heterogeneity of minerals.