By considering the rotary hearth furnaces direct reduction process, using bamboo charcoal, charcoal, straw fiber and coal as reductants, the experimental study on the influence of reduction has been conducted from metallization rate, compressive strength and volumetric shrinkage. The results show that biomass reductants can replace traditional reductants used in the RHF direct reduction process. Compared with traditional reductants, biomass reductants have less affect on metallization rate, but different biomass reductants have large influence on strength and volumetric shrinkage of pellets. The compressive strength of pellet with straw fiber is relatively higher, and the compressive strength of pellets with charcoal or bamboo charcoal is low, but it can be improved at higher temperature(1 300 ℃) for reaching the production requirement. Using bamboo charcoal as reductant will lead to the swelling of pellets in the beginning stage, and this situation will make the volumetric shrinkage at high temperature lower, which will affect the strength of pellets and the heat-transfer between different material layers. Thus it would be better that bamboo charcoal should be used with other reductants.