Rapid industrialization has brought Nam-Hae area serious environmental problems associated with released oil and other hydrocarbons. In this work, in order to enhance the quality of the shoreline sediment we made enviro-chemical analyses of its substances, TPHs and microbial growth after treating with oxygen releasing compound(ORC) such as $MgO_2$. Total organic compound(TOC) was reduced from 33.45% to 25.1~31.08% meanwhile COD decreased from 27.5~28.9mg/$g{cdot}dry$ to 19.9~26.1mg/$g{cdot}dry$ for input of 2~10% $MgO_2$ in 20days. For 10% $MgO_2$ input, TP and TN were reduced by 13.3% and 18.8%, respectively. Most of all TPH was decomposed by max. 42.4% in 21days, and the total viable count of microbes was found to be exponentially increased by 75.9%.