In this study, aerodynamic characteristics of Kline-Fogleman airfoils are numerically investigatied which has been widely used in remote control aircraft operating at low Reynolds numbers. The comparison of aerodynamic characteristics was conducted between NACA4415 and Kline-Fogleman airfoil based on NACA4415. ANSYS Fluent was employed with the incompressible assumption and $k-{omega}$ SST turbulence model. It was found that lift coefficient was significantly enhanced in the range of Reynolds number from $3{ imes}10^3$ to $3{ imes}10^6$. Especially in the region of Reynolds number below $2.4{ imes}10^5$, the lift-to-drag-ratio was improved by 26% using the Kline-Folgeman airfoil compared with NACA4415 airfoil.