Abstract: The present invention relates to a process for preparing raw material containing small amount of quinoline-insoluble component for producing carbon material, comprising the steps of admixing a heavy oil of coal origin or of petroleum origin with an organic solvent having a boiling point of lower than 150.degree. C. and a surfactant which is soluble in the heavy oil and has de-foaming property and de-bubbling property, stirring the thus formed mixture gently with a motive power in a range of 0.5 to 50 watt/m.sup.3 of the mixture, subjecting the mixture to centrifugation thereby removing the solid impurities, and distilling the remaining liquid thereby removing the light fraction to obtain the raw material.