In this paper, a further extended Jacobi elliptic function rational expansion method is proposed for constructing new forms of exact solutions to nonlinear partial differential equations by making a more general transformation.For illustration, we apply the method to (2+1)-dimensional dispersive long wave equation and successfully obtain many new doubly periodic solutions. When the modulus m → 1, these solutions degenerate as soliton solutions. The method can be also applied to other nonlinear partial differential equations.