Carbonization temperature and carbonization time are two important parameters during the carbonization of bamboo, but the concentration of oxygen in the furnace must also be considered. Effects of oxygen concentration in furnace on carbonization of bamboo were examined by controlling and detecting the oxygen partial pressure with an oxygen sensor and regulating the flow of nitrogen and air. The results showed that charcoal yield decreased with the increase of oxygen partial pressure in furnace. Therefore, the concentration of oxygen should be strictly controlled, to form high temperature pyrolysis in hypoxic environment in the traditional process of carbonization. To prevent spontaneous combustion of charcoal, the atmosphere in which the process of carbonization of bamboo should be either neutral and in accordance to the equilibrium diagram of oxygen partial pressure or a high temperature reductive atmosphere.