MapBio is a project initiated by the Chinese Academy of Sciences, which aims at integrating species distribution data from different sources and mapping the biodiversity of China to support biodiversity research and biodiversity conservation decisions. Species distribution data may be found in journal articles, books and different databases in various formats, and most species distributions are described in free text. MapBio is trying to build up a workflow for collecting this free text, parsing it into standardized data and projecting distributions onto a map for each species in China. A map module of MapBio is designed and implemented based on Web GIS to visualize species distributions on a map at different levels, e.g., occurrence points, county, province, distribution range, protected area, waterbody, biogeographic realm. Since the completeness of distribution data is very important for assessing biodiversity, we developed a tool in MapBio for analysis of the gaps in distribution data. Based on the species distribution data, especially the occurrence data, MapBio provides an integrated modeling tool for helping users to build species niche models. MapBio is an open access project. Users can get data and services from it easily for biodiversity research and conservation, and also can contribute their own biodiversity data to MapBio.