The change of connexin 43 (Cx43) expression and the biological behaviors of Cx43 in rat heart cell line H9c2, expressing Wnt-3a (wingless-type MMTV integration site family, member 3A), were evaluated in the present study. Plasmid pcDNA3.1/Wnt-3a was constructed and transferred into H9c2 cells. The cell model Wnt-3a(+)-H9c2 steadily expressing Wnt-3a was obtained. Compared with H9c2 and pcDNA3.1-H9c2 cells, the expression of Cx43 in Wnt-3a(+)-H9c2 cells was clearly increased, the proliferation of Wnt-3a(+)-H9c2 cells was significantly changed, and cell migration abilities were also improved(P<0.05). In comparison with H9c2 and pcDNA3.1-H9c2 cells, the G2 phase of the cell cycle increased by 11% in Wnt-3a(+)-H9c2 cells. Thus, Wnt-3a overexpression is associated with an increase in Cx43 expression and altered migratory and proliferative activity in H9c2 cells. Cx43 might be one of the downstream target genes regulated by Wnt-3a.