Silicated graphite is a new type carbon-graphite base compound material characterized by excellent performance and extensive application. Physical property and silication condition of carbon graphite base material are two key factors affecting silicated graphite preparation by LSP method. According to plenty of tests the physical property of the base material must have expansion coefficients between 3.7×10-6/℃and 5.3×10-6/℃and approximately match the SiC expansion coefficient; the base material must be isotropic and experience graphitization; the porosity is about 50% and the open holes possess no less than half of total holes;the smaller the open holes and the bigger the inside and outside surface areas, the better the condition will be.The optimum silication conditions seem to be 1 900℃~2 000℃in temperature, 1 h in time, more than two times of silication and vacuum degree≥10-3Pa.