: In this paper a proposal for the Biology Petri Net Markup Language (BioPNML) is presented. The concepts and terminology of the interchange format as well as its syntax that is based on XML (eXtensible Markup Language) are introduced. BioPNML is designed to provide a starting point for the development of a standard interchange format for Bioinformatics and Petri nets. The language will make it possible to present biology Petri net diagrams between all supported hardware platforms and versions. It is also designed to bridge Petri net models to other known metabolic simulators.