This　paper　investigates　the　flame　extension　height　induced　by　a　horizontally　oriented　rectangular　source　fire　impinging　on　a　vertical　plate,　which　has　rarely　been　reported　in　literature.　Focusing　on　the　scenarios　with　nonimpinging　flame　lengths　that　are　comparable　with　or　larger　than　the　plate-source　distance,　a　series　of　numerical　experiments　were　conducted,　in　which　the　exit　velocities　varied　from　27.5　to　125　m/s　and　the　orifice　aspect　ratios　ranged　from　1　to　4.　Results　show　that　the　flame　extension　height　increases　with　increasing　exit　velocity　and　becomes　larger　with　increasing　orifice　aspect　ratio　at　a　given　fuel　exit　velocity.　New　correlations　are　proposed　to　predict　the　flame　extension　height　based　on　the　unburnt　fuel　after　impinging,　assuming　a　kite　flame　shape　of　circular　and　elliptical　cross　section.　Moreover,　the　new　proposed　correlations　provide　a　general　and　practical　basis　for　estimating　the　flame　extension　height　of　horizontally　oriented　rectangular　source　impinging　jet　fires.