This study was performed to build up the ecological guidelines to grasp the structure of the vegetation change which is due to river rehabilitation. Anyway, river ecosystem and function has been destroyed owing to river development. It is important that river vegetation supplies ecological corridor and biotope. Two survey sites(Wonsungcheon and Pungseocheon)were investigated in the aspect of plant ecosystem and structure to settle the practical concept of river ecosystem. Each survey site was subdivided to five plots. The site was surveyed through the belttransect method. Wonsungcheon gets more seriously polluted as it runs to the urban area. In other words, there are On the other hand, Pungseocheon has more naturality but its downstream is under the pressure of various wood plants in the upstream area, but downstream area is dominated by naturalized plants such as Bidens frondosa, Panicum dichotomiflorum, etc. Riverbank of downstream has been changed into farm and parking lot. development. It should be preserved definitely because it still has abundant naturality and wetland which formed a biotope. The objective of the research is to find out the river retrogression and maintenance methods based on the riparian vegetation structure. To manage the river ecologically, hydrophytes should be induced partly for natural purification after the riverside is rehabilitated. The vegetation should be induced step by step to restore natural river and steady monitoring and research are required.