The present disclosure relates to an arc ventilation system of a distributing board, and more particularly, to an arc ventilation system of a distributing board to minimize an arc flowing forward to prevent damage. In the arc ventilation system of a distributing board in which a plurality of compartments are provided, a first compartment accommodating an electric power device which can be drawn in or out, among the plurality of compartments, comprises an arc blocking part blocking a space between the electric power device and the first compartment at an operation position of the electric power device.