Abstract: After analyzing the attribute reduction algorithm based on rough set, a new definition of indiscernibility degree was given for mcasurcing the importance of attribution, and the property of indiscernibility degree was analyzed.Then based on the indiscernibility degree, a new heuristic reduced algorithm was proposed, which is useful to deal with the noise and makes the worst time complexity cut down to max(O(∣A∣∣U∣),O(∣A∣2∣U/A∣)).The theoretical analysis and experimental results show that this new method is not only useful in solving data noise but also robust and efficient.

Key words: Rough set, Complete, Reduction, Indiscernitility relation