Classic rough set theory solves problems by means of indiscernibility relation,but it is powerless to resolve the sequencing classification problems in which qualitative attributes,quantitative attributes and criteria exist at the same time.In view of this situation,classic rough set theory is extended,and then a decision analysis method based on the extended rough set theory is proposed.This method replaces the indiscernibility relation in original rough set theory with the indiscernibility-similarity-dominance relation and achieves rough approximation of knowledge.An example study shows that the method can effecively resolve the above mentioned problems and can deal with inconsistence in decision table.