Let G=(V,σ,μ) be a connected fuzzy graph with n-vertices and m-edges. The degree sum of any two arbitrary vertices u and v in a fuzzy graph G is defined as σ(u)d(u)+σ(v)d(v). Then the degree-distance index DDf(G) of a fuzzy graph G is defined as the sum of the distance between every pair of vertices together with their degree sum. In this paper, the degree-distance index DDf(G) of a connected fuzzy graph is introduced and we investigate DDf(G) of fuzzy Mycielskian graph and partial complement of fuzzy Mycielskian graph of a connected fuzzy graph G.