In this paper, we develop a fractional cyclic integral and Routh equation for constraint mechanical systems defined in terms of fractional Caputo derivatives.The fractional Hamilton principle and the fractional Euler-Lagrange equation of the system are obtained under a combined Caputo derivative.Further more, we have also studied the fractional cyclic integrals based on the Euler-Lagrange equations and the associated Routh equations of the system are presented.