A classification of pentavalent symmetric graphs of order twice a prime square is given. It is proved that such a graph is a coset graph of Z3.A6 （non-split extension）, or a bi-coset graph of an extra-special group of order 125, or the standard double cover of a specific abelian Cayley digraph of order a prime square.
Let Γ be a finite connected locally primitive Cayley graph of an abelian group.It is shown that one of the following holds:(1) Γ = Kn,Kn,n,Kn,n-nK2,Kn ×···× Kn;(2) Γ is the standard double cover of Kn ×···× Kn ;(3) Γ is a normal or a bi-normal Cayley graph of an elementary abelian or a meta-abelian 2-group.
