The difficulties in dealing with the Bioinformatics data come more from its idiosyncrasies than from its quantity Currently researchers need to an easy method for data exchange, manage, update. In order to integrate and manage all kinds of biological data, it is reasonable to adopt XML as standard tool since XML is independent of operating system, programming language and hardware platform. Although XML in Bioinformatics has been used widely as a standard notation abroad, however it is the beginning step in the domestic research. This article reviews a basic concept of XML and how to apply XML modeling in Bioinformatics. In addition we present XML applications for genomic sequences, structures and genetic network modeling.