A shock absorber according to the present invention for use in a vehicle for cushioning a vibration generating between a vehicle body and an axle, in which a suspension spring is disposed between one member which may serve as a mass below the spring and the other member which may serve as a mass above the spring, has an apparatus for adjusting the height of vehicle permits its mounting length to be adjusted without changing an initially set load of the suspension spring while being relatively displaced with respect to the one member so that a stroke of the shock absorber may be changed.