Sprawl seems an inevitable phenomenon because of the rapid expansion in urban area. It has some negative consequences, such as long transport distance to work, high car dependence and inadequate facilities. Recently, it pointed as causing a lot of urban problems and the situation has been worsening. This thesis asks the question: could there be a conscious way to prevent this issue? To deal with it, this thesis firstly conducts an intensive study about theories of compact city and satellite city. In the second part, in order to investigate how those theories are reflected and implemented in real examples, this thesis analyzes two cases and discusses about how urban sprawl happened in London and Shanghai as well as to what extent theories were served in these two cities. The investigation produces some results related to the process of urbanization, common actions which authorities would take towards it, and some highlights in the pre-experience. So when facing with urban sprawl, the measure might be dealt with it in a more conscious way.