Abstract：In order to grasp the different influence degree of various factors on the risk assessment of ground collapse in mined out area and a link between some factors,Rough set was adopted to evaluate the risk of ground collapse in mined out area. The theory has strong ability of data mining and knowledge discovery,and the core idea is knowledge reduction. That is,the theory can delete the attributes of the weak and the poor in the collection attributes,and then build the objective and reliable evaluation model. Taking the goaf surface subsidence information of the No. 8 Mine of Pingdingshan Tian'an Coal Mining Corp. Ltd as example,combining with the field survey data,the goaf surface subsidence is evaluated. Evaluation result is close to the fact,therefore,it is feasible to evaluate the risk of goaf surface subsidence by using the Rough set.

Keyword：goaf;surface subsidence;risk evaluation;Rough set;