This study is to examine the public participation activities in the progress of the design competition, purposed to provide urban public spaces by the reuse of industrial heritages. Through the case studies of Berlin Tempelhof Parkland, Mapo Depot and Seoul Station 7017, following activities are common: citizen idea competition, forum, field trip, survey and winners exhibition. However, those activities are more closely organized to the competition process in Tempelhof Parkland, than other tow projects of Seoul Metropolitan Government. Also, it enables to clear and develop the public ideas more that those programs such as survey, citizen idea competition and field trip, are linked to each other in the case of Tempelhof Parkland. It could be achieved by the unified organization between competition preparation and public participation operation.