Abstract: In order to solve the problem that the attribute reduction algorithm based on discernibility matrix spends a lot of time and space and the efficiency of the attribute core and the attribute reduction update of the rough set are slow,what is more,it lacks the incremental updating algorithm for attribute reduction,this paper proposed an incremental updating algorithm for attribute reduction based on the discernibility matrix.When the algorithm updates the discernibility matrix,it only needs to insert a row and a column,or delete a row and modify the corresponding column,which can effectively improve the updating efficiency of core and attribute reduction.We analyzed the relationship of the new object x with the original decision system object,giving out the updating algorithm of the attribute reduction increment.Theoretical and experimental analysis shows that the proposed algorithm can improve the updating efficiency of attribute reduction,reducing the time and space complexity significantly.

Key words: Discernibility matrix,Attribute reduction,Rough set,Original decision system