The purpose of this work was to research the behaviour of carbon in the process of producing silicon. Carbon material is the main and important raw materials in silicon production because silicon is produced mainly by silica and carbon materials in silicon industry. So the chemical composition and reactivity of carbon material are the crucial properties to the metal yield and purity. In this work, the carbon content and behaviour in the silicon or ferrosilicon are also the main issue. In addition, where and how carbide can be formed in the furnace is the focal point.