Abstract:microRNAs (miRNAs) are endogenous non-coding RNAs that are 20-25 nucleotides (nt) in length, and regulate plant development and stress responses at post-transcriptional levels. MicroRNA172 (miR172) is a highly conserved miRNA family in plants that are crucial for phase transition,organ development and stress responses through repressing the APETALA2(AP2) or AP2-like genes encoding AP2/AP2-like transcription factors. Recently,miR172 has been identified as a key regulator of nodulation in legumes and tuber formation in potato. Here, we summarize the major findings on the miR172-mediated plant development and stress responses and discuss the recent progress that has improved our understanding of the growth regulation and plant response to abiotic stresses by miR172-mediated networks.