Abstract: In this paper,the air environmental pollution of Miluo City,Hunan province is taken as an example.According to the obtained data of SO₂,NO_x and TSP in the air,based on the national criteria of 3 degrees for the assessment. Using overstundard weisht grey situation decision method and computer to process these data,the assessment result is all that could be desired. This method will offer a new tool for urban environmental qualitative assessment.