Grey Clustering Judgement on Slagging Performance of Coal Wang Guiming Xie Junlin Postgraduate Student,Silicate Engineering Key Lab.of Education Ministry,WUT,Wuhan 430070,China.This experiment is researched the slagging property of representative coals, and use the grey clustering method to judge the slagging property of various kinds of coals, the results are proved by X ray diffraction analysis, and it provides a exact gist to judge the slagging property of various kinds of coals.grey clustering; slagging; phase diagram;\ coal