Abstract: Ash fusibility was the main basis for slagging evaluation. Some kinds of Zhundong coal with high ash fusion temperature still slagged seriously. In order to analyze the correlation between Zhundong coal fusibility and ash composition,the coal quality data were analyzed in the paper. The results showed that,high basic oxide in coal ash led to high fusibility of Zhundong coal. The fusion temperature of Zhundong coal had a good correlation with basic oxide components,the ash fusibility could be preliminarily judged by the ratio of basic oxides and sum of basic oxide and acid oxide or equivalent basic oxide. This conclusion provided reference for coal ash fusion temperature test,boiler design and power plant safe operation of Zhundong coal.