The propagation characteristics of a negative surface discharge having a rectilinear channel configuration were experimentally investigated under atomospheric conditions. To obtain such propagation, we employed a needle to knife-edged electrode system incorporating a thin dielectric film (PET, δ=50μm) and applied a negative impulse voltage (-8kV, 0.23/24μs) to the needle. Unlike the well-known surface discharge which indiscriminately spreads out in a stream from an electrode, in our system the discharge rectilinearly propagates along the knife-edged electrode. Moreover, a fairly large current flows along the channel and strong illumination occurs. A high-voltage probe was set up at half the length of the generated channel, being capable of measuring its potential distribution. The resistance of the channel was estimated using a relation between its potential difference and a current. The capacitance was also estimated using a relation between the charge and the potential distribution. In addition, e briefly discuss a model describing the propagation behavior of the rectilinearly channeled negative surface discharge.