A variable displacement vane pump is provided and can inhibit shocking pressure during low-seed rotation. A zone between the terminal end (D) of a discharging port (44) and a starting end (A) of an inhalation port (43) is adopted as a first confining zone. A zone between the terminal end (B) of the inhalation port and a starting end (C) of the discharging port is adopted as a second confining zone. When a circumferential middle point of the starting end of the inhalation port and the terminal end of the discharging port is adopted as a reference point and a line perpendicular to a rotation axis (O) of a driving shaft (5) of a rotor (6) and passing through the reference point is adopted as a reference line, a cam supporting surface (93) formed in the inner circumferential side of a pump accommodating part is formed in a manner that the shortest distance between the cam support surface and the reference line decreases from the second confining region side toward the first confining region side, and the motor (8) is formed in a manner that a cam profile radius change rate decreases first and then increases again on the second confining region side when eccentric amount delta of the motor (8) is maximized.