Family of betaNACtes genes in the Drosophila melanogaster genome is a model to investigate the mechanisms of molecular evolution of recently evolved genes. The betaNACtes genes encode proteins, homologous to beta subunit of nascent polypeptide-associated complex (NAC), are expressed in testes and localized on the X chromosome as two two-gene clusters and one separate copy. We collected population polymorphism data for betaNACtes genes using several wild-type stocks of D. melanogaster and compared betaNACtes paralogs with each other. We have shown heterogeneous pattern of betaNACtes genes polymorphism: genes in 3' region of two-gene clusters are low polymorphic, whereas separate betaNACtesl gene is most variable. 5'betaNACtes copies in two-gene tandems are practically identical, whereas 3'betaNACtes copies are highly diverged. Thus, we propose local gene conversion providing selective homogenization of 5'genes. Comparison of betaNACtes paralogs has shown that majority of amino acid differences are in N-terminal part of proteins, containing betaNAC domain. McDonald-Kreitman test of betaNACtes paralog divergence shows the involvement of positive selection in the course of betaNACtes gene family evolution.