Carbon composite iron ore hot briquette (CCB) is a new type of iron-making raw materials,which is made through hot briquetting by binding coal and iron ore fine. The reducibility is one of major metallurgical properties for iron-making burdens. The reacting gas composition and temperature effecting on the reducibility of CCB have been studied through the experiments of reduction weight loss in this paper. The experimental results show that the whole reduction process of CCB could be divided into two stages. The reduction rate during the first stage is significantly faster than that during the second one. The temperature has a significant effect on reduction rate; with the increasing temperature, the reduction rate tends to fasting while the reducing gas composition unchanged. Reacting atmosphere has a significant effect on reduction process of CCB at temperature 900℃,and reducible atmosphere has the most important influence on the reduction rate; but at temperature 1100℃, the effects tends to decreasing.