Cleaner production assessment is a measure of the state and level of cleaner production, also a necessary method of promoting cleaner production in enterprises. For the purpose of the improvement of cleaner production of enterprises, improved Analytic Hierarchy Process (AHP) model and grey relational analysis (GRA) are used to assess the same nature of the three enterprises of one group with seven quantitative indicators concordant with the Cleaner Production Report. The results are consistent with the clean production reports from three enterprises, which show that the integrated methods are feasible and objective, and can be used as a tool for internal cleaner production assessment.