A stroke sensor system comprising: a vehicle-body-side member formed in a tubular shape and located at a vehicle body side; a wheel-side member formed in a tubular shape, located at a wheel side, coupled to the vehicle-body-side member, and configured to move relatively to the vehicle-body-side member in an axial direction of the vehicle-body-side member; and a movement-amount deriving section configured to derive a movement amount of relative movement between the vehicle-body-side member and the wheel-side member, wherein at least a part of one of the vehicle-body-side member and the wheel-side member is an electric conductor, and the other of the vehicle-body-side member and the wheel-side member is provided with a coil, characterized in that the movement-amount deriving section comprises: an even number of capacitors (C1, C2) electrically coupled to the coil and configuring an LC resonance section; and an even number of exciting sections (H1, H2) for exciting an oscillation waveform output by the LC resonance section depending on the relative movement between the vehicle-body-side member and the wheel-side member, wherein the even number of capacitors (C1, C2) and the even number of exciting sections (H1, H2) are divided into a plurality of groups of same number of the capacitor (C1, C2) and a plurality of groups of same number of the exciting section (H1, H2) respectively to configure a balanced circuit, the movement-amount deriving section is adapted to derive the movement amount based on the oscillation waveform, and a resonance frequency of the LC resonance section changes according to the relative movement amount between the vehicle-body-side member and the wheel-side member due to a movement dependent variation of the inductance of the coil. a vehicle-body-side member formed in a tubular shape and located at a vehicle body side; a wheel-side member formed in a tubular shape, located at a wheel side, coupled to the vehicle-body-side member, and configured to move relatively to the vehicle-body-side member in an axial direction of the vehicle-body-side member; and a movement-amount deriving section configured to derive a movement amount of relative movement between the vehicle-body-side member and the wheel-side member, wherein at least a part of one of the vehicle-body-side member and the wheel-side member is an electric conductor, and the other of the vehicle-body-side member and the wheel-side member is provided with a coil, characterized in that the movement-amount deriving section comprises: an even number of capacitors (C1, C2) electrically coupled to the coil and configuring an LC resonance section; and an even number of exciting sections (H1, H2) for exciting an oscillation waveform output by the LC resonance section depending on the relative movement between the vehicle-body-side member and the wheel-side member, wherein the even number of capacitors (C1, C2) and the even number of exciting sections (H1, H2) are divided into a plurality of groups of same number of the capacitor (C1, C2) and a plurality of groups of same number of the exciting section (H1, H2) respectively to configure a balanced circuit, an even number of capacitors (C1, C2) electrically coupled to the coil and configuring an LC resonance section; and an even number of exciting sections (H1, H2) for exciting an oscillation waveform output by the LC resonance section depending on the relative movement between the vehicle-body-side member and the wheel-side member, wherein the even number of capacitors (C1, C2) and the even number of exciting sections (H1, H2) are divided into a plurality of groups of same number of the capacitor (C1, C2) and a plurality of groups of same number of the exciting section (H1, H2) respectively to configure a balanced circuit, the movement-amount deriving section is adapted to derive the movement amount based on the oscillation waveform, and a resonance frequency of the LC resonance section changes according to the relative movement amount between the vehicle-body-side member and the wheel-side member due to a movement dependent variation of the inductance of the coil.