The COREX, an alternative ironmaking process, still has some gaps to reach the designed production. The metallization degree is regarded as one of the limitations of the COREX process. In the present work, several parameters affecting metallization degree of direct reduced iron (DRI) are analysed by SPSS software. Melting rate, oxidation degree of reducing gas, oxidation degree of top gas, top gas consumption per ton burden, temperature of reducing gas, and burden distribution index are confirmed as the main factors affecting metallization degree. Based on this, a linear equation has been developed for predicting metallization degree. What’s more, improving the melter gasifier vault temperature appropriately, increasing the proportion of high volatile matter coal, and optimizing the type and particle of iron ore and pattern of burden distribution are advised to improve the metallization degree.