Abstract: The problem of complementary cycles in tournaments was completely solved. However, for semicomplete multi-partite digraphs, the problem of complementary cycles is still open. In 1999, Yeo presented conjecture which a diregular multipartite tournament has a pair of complementary cycles. In this paper, based on the definition of componentwise complementary cycles, we get the following result. If D is a diregular n-partite ( ) tournament, then it contains a pair of componentwise complementary cycles C1 and C2, unless it is isomorphic to T71. This result gives impetus to resolving Yeo's conjecture and the problem of complementary cycles in multipartite digraph.