miR397 is one of the conserved miRNAs in plants. In different plants, the miR397 family is mostly composed of one to three members. Through regulating the laccase gene and other genes, miR397 is widely involved in regulating plant growth, development, and stress responses, thus affecting important economic traits such as seed yield and fruit quality. Therefore, as a target gene of molecular breeding, miR397 has great application potential in plant genetic improvement. In this article, the distribution of miR397 in plants, the identification of target genes of miR397, and the regulating roles of miR397 in plant growth, development, and stress responses were reviewed, and the problems that remain to be solved are pointed out, which provides a reference for the application of miR397 in plant genetic improvement.