The room temperature strengths of chromite solid carbon mixing pellets were investigated experimentally and theoretically by varying the reaction temperatures from 1200 to 1400℃ and reaction times from 1hr, to 2hrs. The following results were obtained. 1) The strength of firing pellets was found to increase with temperature but decrease with firing time. This is thought due to the gasified reaction of carbon. 2) From the break down pattern of fired pellets the strength of pellets appears to originate mainly from the slag banding of particles in pellets at an early stage of reduction process, while the strength at the later stage is caused by metal banding. 3) The coke mixing pellets showed the highest room temperature strength among the three pellets tested in this study.