An elevator rope braking system is provided, in which an elevator hauling rope is temporarily supported and locked by the operating plate equipped with a brake lining and which operates by a hydraulic pressure, when the elevator slowly moves due to slippage of the rope or operates at a speed higher than the normal speed, so as to thereby prevent the elevator from slippage or over-speed and achieve a safe operation of the elevator. The elevator rope braking system is installed at the rope side where the elevator is installed or the rope side where the balancing weight is installed, from among ropes caught at the lifting pulley arranged in a machinery room having a winch mounted therein. The elevator rope braking system includes a hydraulic pressure generating unit having a directional solenoid valve and a pressure accumulator which operate in accordance with a signal output from a controller of an elevator; a driving unit having a hydraulic cylinder which receives a driving force from the hydraulic pressure generating unit, an elastic spring and a connection member; and a locking unit having a fixed plate both ends of which are fixed to a housing, and an operating plate which advances or retreats against elastic force of a plurality of springs.