Conservation of historical cities, as a complex project with social practice, presents requirements for promoting urban conservation concepts as well as improving operating methods. Urban design is not only a concept attaching great importance to urban overall quality, but also an effective comprehensive method for improving urban environment, as well as a public strategy of controlling and leading the development of urban space. Urban design, as an important planning tool processing the urban historic context, quality of space environment, aesthetic need dynamically, plays an important role in improving methods of conservation of historical cities. This paper summarizes the eastern and western thinking and its impact on conservation of historical cities, and proposes an integrated urban design method of conservation of historical cities and development.