Abstract: The structure of the bonding phases of sinter depends on the properties of melts formed during iron ore hematite sintering. A bench-scale test was therefore carried out to investigate the effect of powdered iron ore composition (SiO2, Al2O3, MgO and bacisity) on the sinter strength, of which the change was further explained by the effect of the composition on the viscosity and surface tension of the melt. The results showed that the mass ration of additive CaO to the powdered ore changes in the range from 0.08 to 0.15 and the max compression and rupture strength of sinter are obtained at the ration=0.12 and, with respect to the changing basicity during sintering, the max strengths are obtained at the basicity R=2.0. The strengths decrease gradually with the increasing MgO content in hematite, and it is unfavorable if the Al2O3 content exceeds 2.5wt%.