In this paper, we study a numerical method for solving Nth-Order fuzzy differential equation (NOFDE). A Characterization Theorem that is presented shows that the NOFDE is equivalent to system of ODEs. So the numerical method for ODE can be used for NOFDE. Two examples are provided.

In this paper, fuzzy variational iteration method (FVIM) is proposed to solve the second- order fuzzy Abel-Volterra integro-differential equations. The existence and uniqueness of the solution and convergence of the proposed method are proved in details. is investigated to verify convergence results and to illustrate the efficiently of the method.