A fixed rf frequency acceleration scheme is required for rapid-acceleration and producing high-intensity beam in non-relativistic energy region. For these requirements, new-type of fixed rf frequency acceleration scheme called serpentine acceleration is applied in scaling FFAG. To examine a longitudinal motion with serpentine acceleration, longitudinal hamiltonian in scaling FFAG with fixed rf frequency is derived analytically. Then details of serpentine acceleration scheme in scaling FFAG are presented. To demonstrate serpentine acceleration in scaling FFAG, beam experiment has been done with electron scaling FFAG ring. Results are analyzed and confirm the serpentine acceleration in scaling FFAG. Finally, longitudinal design for ADS proton driver with this scheme is presented. © 2013 Elsevier B.V.