This study was surveyed to know changing flora between pre and post of restoration in cheonggyechon. As results, it was surveyed families 33, species 94 in 2003 and families 39, species 156 in 2005. In 2006, it was surveyed families 38, species 171. This result shows that cheonggyechon is unstable initial condition in restored stream ecosystem. Also, Naturalized species was 19 species in 2003 and it was respectively 44, 46 species in 2005, 2006. Hazard species of ecosystem was in common 3 species in three surveys. Recently, as time goes by, introduced species are increasing. And succession has mainly been progressed by one year or binary herbs. To administer restored stream ecosystem, monitoring is essential. Therefore, continuous monitoring about Naturalized species and Hazard species of ecosystem is also very important. Further, Because change of vegetation on pre and post of Restoration in Cheonggyechon Stream is very important, Monitoring will have been surveyed continuously.