The effects of water temperature, salinity and irradiance on the growth of harmful algae Chattonella marina isolated from Gamak Bay in South Sea, Korea were investigated. C. marina was able to grow in temperatures of $15-30^{circ}C$ and salinities of 10-35 psu. Maximum specific growth rate (0.64/day) was observed with combination of $25^{circ}C$ and 25 psu. Optimal growth (${ge}70%$ of maximum specific growth rate) was obtained with all salinities of the above $20^{circ}C$. This result indicated that C. marina is a stenothermal of the high water temperature and euryhaline organism. C. marina was did not grow at irradiance ${le} 10{mu}mol$ photons/($m^2;s$). Photoinhibition did not occur at $300{mu}mol$ photons/($m^2;s$), which was the maximum irradiance used in this study. The irradiance-growth curve was described as ${mu}=0.78(I-11.4)/(I+34.1)$ at $25^{circ}C$ and 25 psu. The half-saturation photon flux density (PFD) ($K_s$) was $56.9{mu}mol$ photons/($m^2;s$) and compensation PFD ($I_c$) was $11.4{mu}mol$ photons/($m^2;s$). The result of the present study indicate that C. marina has advantage physiological characteristic to the interspecific competition at the embayment and costal areas of South and West Sea, Korea in summer.