MicroRNAs (miRNAs) are an extensive class of endogenous, non-coding, short (21~25 nt) RNA molecules, which regulate expression of target genes through miRNA-guided cleavage or translational repression of mRNAs. Plant miRNAs are involved in all aspects of regulation of plant growth and development. The miR319 was shown to regulate TCPs transcription factor controlling the fate of plant organ growth such as leaves and flowers and was involved in regulating part of hormone biosynthesis and signal transduction pathways. Thus, they play a key biochemical function in plant organs development. This review focused on the key roles of miR319 in regulation of the morphogenesis, development, and senescence of plant organs such as leaves and flowers.