Riparian zone,an ecotone between land and river,is an important component of a river.It is also very significant to human’ s production and livelihood.Based on a variety of domestic and foreign evaluation systems and combined with the water characteristics and field instigation of the Andamu River,16 indicators are selected for the naturalness evaluation index system that matches both in structure and functions by using the methods of hierarchical analysis and vague integrated appraisal.Under the comprehensive consideration of the geological features and community characteristics of a balanced riparian ecosystem,the nearnatural levels of a riparian zone can be classified into four grades:natural state,nearnatural state,degrading state,and degraded state.The evaluation results of the Andamu River by using the naturalness evaluation index system match the actual conditions.The naturalness evaluation index system may be applied as a suitable evaluation system for the riparian zones in Beijing sunburn.