The main objectives of this research are to analyse and evaluate the demolishing walls initiative in Daegu city as the collaborative urban environment improvement initiative in South Korea using the actor network theory concept. Local authorities are unable to effectively and efficiently improve urban environment because of their limited statutory and financial powers. This inability crucially led to the formation of the demolishing walls initiative in Daegu city with building a coalition of the local people, interest groups and public and non-governmental organisations in the operational processes in order to improve the physical and social urban environments. Furthermore, co-ordination between local authorities and landscape architecture specialists not only to change the way in which they tackle urban environmental problems but also to make the local people aware of their potential ability in positively improving the urban environment.