Disclosed is a solenoid valve for a brake system. The solenoid valve includes a valve housing installed in a bore of a modulator block and configured to include an internal flow path, a valve sheet provided at the internal flow path of the valve housing and configured to include an orifice, an armature configured to be slidably moved up and down by a magnet core and to include an opening or closing sphere configured to selectively open or close the orifice, a sleeve configured to accommodate the armature therein and to have one end coupled to the valve housing and the other end at which the magnet core is provided, and a damper guide provided at the internal flow path of the valve housing to come into contact with and surround the armature.