Lifted flame stabilization mechanism has been explained with constant Schmidt number, and liftoff height of the flame is determined as a function of * / 2 (2Sc 1)/(Sc 1). In this research, local Schmidt number is suggested in order to measure edge flame propagation velocities directly, and edge flame propagation velocity can be obtained from the trend between lift-off height and nozzle flow rate. As a result, local Schmidt number becomes lower when nozzle flow rate is maximized or minimized, while local Schmidt number is maximized at mean of nozzle flow rate.