Sinter plants currently have to use many types of ores with different properties due to the great demand for iron ores, which was driven by the massive growth in Chinese iron and steel industry. On the other hand, the development of iron ore mines is limited and the quality of iron ores is in a tendency of deterioration. Therefore, the quick evaluation of iron ores has become more important for a stable sintering operation._x000D_
In addition to such a background, the CO2 gas emission should be decreased from sinter plants according to the Kyoto Protocol on reduction in greenhouse gases._x000D_
The present paper first describes the methods for testing the metallurgical properties of iron ores, which use a small volume of sample mainly focusing on magnetite ore that is effective for reducing CO2 and NOx emissions from sinter plants. The sintering properties of ores are evaluated separately according to each stage in sintering process, that is: heating stage before melt formation, primary melt formation in adhering fines layer of pseudo-particles, and assimilation of nucleus ore particle with calcium-ferrite system melts._x000D_
Next, the application of the tests to the blending ores is introduced showing examples of the studies on the effective usage of the magnetite ores with Marra Mamba type ores.