Abstract: Fluorescent carbon dots are one of the most popular carbon nanomaterials after carbon nanotube, nano-diamond and graphene. Owing to its advantages of excellent photoluminescence, small size features, good biocompatibility, low cytotoxicity and ease to achieve surface functionalization compared with conventional semiconductor quantum dots, carbon dots have great application value in the field of environmental detection, biochemical sensing, drug carriers, photocatalytic and electrocatalytic technology and other areas. The progress in composition methods, structure, property and application research of carbon dots are summarized, the bottleneck problems of restricting carbon dots application development are pointed out and main further research direction is prospected.