Abstract: DELTA system developed by Dallwitz et al.is a flexible data coding format for the concise representation and manipulation of taxonomic descriptions, and an associated set of programs for producing and typesetting natural language descriptions and keys. for interactive identification and information retrieval, and for conversion of the data to formats required for phylogenetic and phenetic analysis. This paper is a general introduction to the functions included in DELTA system. We hope that it will promote the spreading and use of DELTA among plant taxonomists in China.