Taking bidding for the Olympics as an opportunity，Beijing Municipal Government published “Beijing 25 films historical and cultural city protection plan in the old city zone”. As the best conservation alley area，the third to eighth Hutong of Dongsi Sub-district was included in the first batch of the traditional residential protection area. With the successful Olympic bid，Dongsi implemented the historical and cultural protective project in western area，the dangerous houses renovation project in the eastern area，and the green Olympic community construction project. They also launched the alley rectification and changed the sources of energy from coal to electricity. These projects not only protected the historic district，enhanced the city landscape，but also improved the quality of environment and the level of infrastructure. Being the center city of megalopolis，great event and urban policy creates opportunity for community development. Meanwhile，the combination of the social forces of the national activities and community transformation is also important. The local government and the community residents autonomy participation is an important safeguard for the smooth transformation of the old city.