Abstract: The planning methods and operation modes of traditional distribution network are difficult to accommodate the high penetration of distributed energy resources（DER）.Active distribution network（ADN）,based on the application of information and communication technology（ICT） and advanced metering infrastructure（AMI）,is one of the alternative solutions.In this paper,the impact of DER on the traditional distribution network was analyzed and thus the necessity of developing ADN was clarified;The basic concept of ADN,its research tendency,the differences between traditional distribution networks and ADN and the corresponding research results were introduced;Some enabling technologies which are cost-effective for the transitions from the existing distribution network to the active distribution network were discussed.With the progress of the available techniques,ADN can balance the power at distribution levels,and between transmission and distribution levels,that is,ADN will be an infrastructure as a regional exchange of all kinds of energy.