This study was carried out to understand the distribution of heavy metals in aquatic environmental samples of the Lake Shihwa. The environmental samples (surface seawater and sediments, settling particulate matters and aquatic organisms) were collected in 2003. Due to extreme pollutant discharge from various kids of anthropogenic sources such as the Banweol and Shihwa Industrial Complexes and cities, the Lake Shihwa has been polluted in waters, sediments and settling particulate matters with various heavy metals. Although the environmental qualities of heavy metals in the lake have been improved partially due to inflow of outer seawater, it is not clear to reach a good environmental quality. Therefore, further environmental programs should be conducted continuously for environmental improvement