Abstract: The h-restricted arc-connectivity of a digraph is an important parameter to measure fault-tolerance of interconnection networks. This paper determines that the h-restricted arc-connectivity of the Harary digraph D = G(n; 1, 2, …, k) is equal to n/2 for 2≤h≤n/2, k = 2 and n is even, and λ_h(D) = g(k - 1) for 2≤h≤g and 3≤k <n/2, where g is the girth of D. As consequences, the super restricted arc-connectedness of Harary digraph D is obtained immediately. In particular, for k = 2 and n is even or 3≤k < n/2 and n can be divided by k, it can be determined that distinct positive (respectively, negative) λ_h-superatoms of D are vertex disjoint for 2≤h≤g.

Key words: Restricted arc-connectivity, λ_h(D), Super-λ_h, λ_h-Atom, λ_h-Superatom