A label printing device is disclosed, which comprises a keyboard having a plurality of numeral keys for inputting an article code, a data generator for generating data necessary for the formation of bar code data according to the article code, a printer and a control unit for forming bar code data having an arrangement predetermined by a bar code format read out from the memory according to data from said data generator and causing the printer to print the bar code data on label. In the memory are stored different bar code formats corresponding to a plurality of operation modes including registration and training. The control unit reads out, according to the input article code and the operation mode selected by the operation mode selection unit, a corresponding bar code format from the memory.