Abstract: The algorithm of concept lattice reduction based on variable precision rough set was proposed by combining the algorithms of汗upper and lower distribution reduction in variable precision rough set with the characteristics of the formal context in concept lattice. The traditional algorithms about value select algorithm, attribute reduction based on discernibility matrix in VPRS were discussed. There are defects in these traditional algorithms which are improved. Finally, the generation system of concept lattice based on variable precision rough set was designed to verify the validity of the improved algorithm. And a case demonstrates the whole process of concept lattice construction. The experimental results indicate that this algorithm has great validity.

Key words: Variable precision rough set, Concept lattice, Attribute reduction, Extraction rule