Nanos genes were required for differentiation of the anterior-posterior body axis in the Drosophila embryo. In addition to this somatic function, the nanos protein plays critical roles in the migration and survival of PGCs in vertebrates and invertebrates, but the regulating mechanisms of Nanos is largely undefined during the embyro development. In this study, we report a novel interaction between zebrafish Nanos and myosin light chain II (Mylz2). This stable complex, which is formed through the RNA-binding zinc finger domain and fourteen amino acids at the C-terminus of Nanos, was confirmed by GST pull-down and co-immunoprecipitation. Both of these two parts are required for the interaction with Mylz2, but ninety-one amio acids at N-terminus of Nanos are not required. Using a phospho-myosin light chain 2 (Ser19) antibody, we demonstrate that Nanos downregulates the phosphorylation of the Mylz2 by cotransfecting PRK-FLAG-Na and PRK-HA-My Mylz2 in 93T cell. We discuss the biological roles of the interaction between Nanos and Mylz2 and the Nanos regulating phosphorylation of the Mylz2 in PGCs.