Graphitizationdegree,latticeconstantandcrystallitesizesofthreekindsofC/Ccompositesweremeasured byrietveldrefinementmethod(wholespectrumfitting)ofX-raydiffraction.Theresultsshowthatstandarddeviationof crystaltheparameterofthethreeC/Ccompositesislessthan2.0×10-3,standarddeviationofgraphitizationdegree(g)is lessthan1.5,standarddeviationofcrystallitesizes(Lc002)islessthan0.5.RietveldrefinementmethodofX-raydiffractionis effectiveforinvestigationofthecrystalparametersofC/Ccomposite.