Seven feeding trials were conducted to determine the effects of feeding rate and frequency in the Korean rockfish Sebastes schlegeli at seven different water temperatures. Two feeding-rate experiments for 5-g Korean rockfish at $17^{circ}C$ and $20^{circ}C$; three feeding rate experiments for 16-g Korean rockfish at $16^{circ}C$ and $24^{circ}C$; and finally, two feeding frequency experiments for 93- and 100-g at $15^{circ}C$ and $20^{circ}C$ were conducted. Twenty fish averaging $5.5{pm}0.2$ g ($mean{pm}SD$) were randomly distributed into 18 indoor tanks containing 40-L seawater from a semi-recirculation system. Fish were fed a commercial diet for 4 weeks at water temperatures of $17^{circ}C$ and $20^{circ}C$. Two feeding trials were conducted to determine the optimum feeding frequency in growing Korean rockfish reared at temperatures of $15^{circ}C$ and $19^{circ}C$. Broken line regression analysis of weight gain (WG) indicated that the optimum feeding rates of 5-g growing Korean rockfish were 4.48% (BW/day; BW, body weight) at $17^{circ}C$ and 4.83% (BW/day) at $20^{circ}C$. Broken line regression analysis of WG showed optimum feeding rates of 16-g juvenile Korean rockfish of 3.41% (BW/day) at $16^{circ}C$, 3.75% (BW/day) at $20^{circ}C$, and 3.34% (BW/day) at $24^{circ}C$. The biological performance, results, along with morphological indices and serological characteristics, suggest that a feeding frequency of 1 meal/day was optimal to improve WG in growing Korean rockfish grown from 93 to 133 g at a water temperature of $15^{circ}C$, and 100 to 132 g at $19^{circ}C$.