Korean bullhead (Pseudobagrus fulvidraco) was collected from the Kum River areas of Kangkyung-eup, Nonsan city, Chungcheongnam-do, Korea, from April to June, 2012 and was fertilized in order to observe egg development and temperature-related cleavage rates and mitotic intervals (${ au}_0$). The fertilized eggs were separative, demersal and light yellowish with $1.5{pm}0.06mm$ in diameter, and did not contain oil globules. The first cleavage stages were 90 min, 80 min, 60 min and 50 min at $21^{circ}C$, $24^{circ}C$, $27^{circ}C$ and $30^{circ}C$, respectively. At higher temperatures, eggs developed faster and underwent further identical development. For Korean bullhead, ${ au}_0$ were $33.4{pm}2.08$ min at $21^{circ}C$, $31.5{pm}3.06$ min at $24^{circ}C$, $28.1{pm}2.11$ min at $27^{circ}C$ and $26.4{pm}3.35$ min at $30^{circ}C$. There were strong negative correlations between the $ au_0$ and water temperatures at all points studied (Y=-1.13X+58.15, $R^2$=0.98, n=30, where Y is ${ au}_0$ and X is temperature). The results obtained in this work will be helpful for chromosome manipulation by use of cleavage frequency data and ${ au}_0$ data in Korean bullhead.