(Pt/Co)5/Ru/(Co/Pt)5 films with different Ru thicknesses were prepared by magnetron sputtering. Oscillatory behaviour of effective perpendicular anisotropy and remanence in the (Pt/Co)5/Ru/(Co/Pt)5 films as a function of the thickness of Ru has been first observed, from which we can obtain the conclusion that the synthetic spin in the (Pt/Co)5/Ru/(Co/Pt)5 films rotates from the vertical direction to the in-plane one periodically with the change of the thickness of the spacer layer of Ru.