Abstract: This article introduces a new distance measure for interval numbers,and extends the PROMETHEE Ⅱ method that can deal directly with the eigen space expressed as interval numbers. On the basis of the analysis of the relationship between the weighted vector and the final priority order,a principle of the weights dete mination of extended PROMETHEE Ⅱ method based on interval numbers for decision attribute is proposed. Through case study,this method,feasible and effective,has high value in popularization and application.

Key words: interval numbers, distance measure, PROMETHEE Ⅱ, weights determination