Disclosed is a valve block of an electronic control brake system. The valve block of an electronic control brake system includes two hydraulic pressure circuits, and a plurality of accommodation bores at which a plurality of valves, a pump, a low-pressure accumulator, a pressure sensor, and a motor are installed so as to control braking hydraulic pressure delivered to a wheel cylinder installed at each of wheels, and a plurality of flow paths configured to connect the plurality of accommodation bores to one another, wherein a pressure sensor accommodation bore, at which the pressure sensor is installed, is provided with at least one wheel cylinder pressure sensor accommodation bore configured to accommodate the pressure sensor which is connected to each of wheel cylinder ports to detect oil pressure, and the at least one wheel cylinder pressure sensor accommodation bore is connected by a sensor connection flow path formed at the valve block, and connects a selected wheel cylinder port among the wheel cylinder ports, which are connected to wheels, to the at least one wheel cylinder pressure sensor accommodation bore by adjusting lengths of a port connection flow path, which is connected to each of the wheel cylinder ports and the sensor connection flow path.