Circular RNAs (circRNAs) are a large class of noncoding endogenous RNAs in eukaryotic that are formed through 3′-5′ ligation of a single RNA molecule. Accumulating studies have shown that circRNAs are abundant, diverse, stable, and cell or tissuespecific expression, etc. Recent studies have shown that circRNAs can act as miRNA sponges to sequester miRNAs, play regulatory roles on the expression of their parent coding genes and bind to RNAassociated proteins to form RNAprotein complexes and regulating gene transcription. However, most of these previous studies are focus on animals and human, very little information is available about the features and functions of circRNAs in plants. At present, circular RNAs have only been identified in rice (Oryza sativa), Arabidopsis (Arabidopsis thaliana), wheat (Triticum aestivum), kiwifruit (Actinidia chinensis), tomato (Solanum lycopersicum), and soybean (Glycine max), their biological functions are much unknown in plants. The present article reviewed circRNAs classification, biogenesis, functions and relative research methods, and summarized the research progress and unresolved issues about circRNAs in plants.