Employing waste agricultural straw into iron ore sintering is a promising approach to realize efficient energy utilization and environmental protection. In this paper, the characteristics of four types of straw-based fuels including raw straw (RS), preformed straw (PS), straw char (SC) and preformed straw char (PSC) were assessed. The results indicate that RS and PS mainly consisted of volatile matters, which was pyrolyzed in the downstream of combustion zone. This property of RS and PS led to lower fuel utilization and then decreased the bed temperature for minerals melting. Recommended replacement percentage of RS and PS to coke breeze was restricted at 10%. Compared with RS and PS, SC had the advantage of improving fuel utilization and ensuring higher bed temperature. But SC showed considerably faster combustion speed than coke breeze, which accelerated sintering speed excessively when SC replacing coke breeze exceeded 20%, and the suitable replacement percentage of SC to coke breeze was 20%. PSC ingeniously integrated the advantages of PS and SC by joint preformation-carbonization process. Comparable sintering performance was achieved when improving the replacement percentage of PSC to coke breeze to 40%, and its capacity for reducing CO2, SOx and NOx emissions achieved 24.5%, 26.6%, and 28.2% respectively. (C) 2016 Elsevier B.V. All rights reserved.