The present disclosure provide compositions, methods and kits for generating a set of combinatorial barcodes, and uses thereof for barcoding samples such as single cells or genomic DNA fragments. Some embodiments disclosed herein provide compositions comprising a set of component barcodes for producing a set of combinatorial barcodes. The set of component barcodes can comprise, for example, n×m unique component barcodes, wherein n and m are integers, each of the component barcodes comprises: one of n unique barcode subunit sequences; and one or two linker sequences or the complements thereof, wherein the component barcodes are configured to connect to each other through the one or two linker sequences or the complements thereof to produce a set of combinatorial barcodes.