Gene flow in nature not only is an essential mechanism maintaining species’ cohesion and impeding genetic differentiation among populations but also can serve as a source of genetic variation generating adaptive divergence and biological dive-rsity. Detailed information about gene flow dynamics on adaptive evolution can help in understanding the underlining mec-hanisms and critical factors driving speciation and diversification in nature. In this paper, we focus on the gene flow dynamics within and among plant populations and review some important developments in the theoretical concepts and empirical studies of gene flow in plants. This review provides references for future trends in this research field.