this paper reviews the evaluation model and measurements according to metropolitan digital library activities. through literature review and historical research, the authors argue that the evaluation of the digital library (dl) is still in a research stage and not yet of value to the real achievement of the dl in operation. because of the variety of the understandings of the digital library and the complexity of the technical factors, we can put forward a set of reference models, measurements and approaches to combine with the various researches on the evaluation theory and practice in the digital area. the authors primarily discuss and conclude with a digital library evaluation model and measurement index system according to the requirements of the world metropolitan libraries.