Abstract: Authors had a new try to the methodology of establishing urban integrated pollutuon control and treatment index system, using the degree analysis to screen the nrban pollution factors, and using ranking generalized fuzzy numbers with trapezoidal membership functions (ie. ranking maximizing set and minimizing set) to compute weights of pollution index for a whole city. Such index system is also used to evaluate the pollution conditions of the surface water of an industrial city and the result of the assessment is in agreement with the actualities.