In this paper, we use the modified reproducing kernel Hilbert space method to approximate the solution of fuzzy differential equations of fractional order. Using this method, we construct a new algorithm to approximate the solution of such differential equations. The proposed algorithm produces solutions in terms of interval-valued fuzzy numbers. Two numerical examples are tested and the results showed that the proposed algorithm is able to produce solutions that approach to the exact solutions. It concludes that the proposed algorithm can be considered as a modern algorithm that complements to the existing ones. c ○2017 All rights reserved.Keywords: Caputo fractional derivative, fuzzy differential equation of fractional order, modified reproducing kernel Hilbert space method. 2010 MSC: 34A08, 34A07, 47B32.