Along with social and economic development in China,the problems of integrated assessment and management of water quantity and quality are more important to sustainable development.Since 1981 of the first national comprehensive water resource assessment,the condition of water resource in China has significantly changed in both outside and internal.The main change focuses on the following two aspects:one is that water quantity has changed because of environmental impact;the other is that water quality has deteriorated due to human activities.To understand distribution of different water quality classes related to a certainty water resources quantity and their change,to develop a comprehensive integrated assessment approach of water quantity and quality is urgently needed.This paper addresses a new integrated assessment method for water quality and quantity based on surface water resources status.Major researches involve two aspects:(1)the assessment method of water quality and quantity applied to lumped or unit water system,in which the time series of both water quality and quantity are integrated in terms of different water quality classes and related water quantity increment;(2)the integrated assessment of water quality and quantity of lumped system is extended to the distributed water system in terms of hydrological system relation.The case study of Luanhe river basin in North China is given as a preliminary explanation of this methodology.It was shown that the new methods are feasible and can directly describe the space-time variation of water quality and quantity of a basin or a region.The integrated assessment results can provide the decision makers with important information on the actual amount of the clear water and non-clear water in a basin or a region and present status of their spatial distributions.This will be helpful for reasonable planning and management of water resources.