Abstract:During the last decades, Astronomy has been stepped into a data intensive era. TB datasets have been in hands, and PB datasets are emerging. Big data in astronomy brings challenges on data management, computing, bandwidth, software, and even the way to do research. Astronomers are working together with experts in computer science and information technology to provide an easy way to discover knowledge from big data. Virtual Observatory (VO) is a data-intensively online astronomical research and education environment, taking advantages of advanced information technologies to achieve seamless, global access to astronomical information. To allow users and applications to access distributed and heterogeneous datasets and services in a consistent and uniform way (interoperability), International Virtual Observatory Alliance (IVOA) has been defined a set of standards and specifications. However, the VO, especially the IVOA, does not address all of the challenges faced to astronomical research and education in a data-driven and data-intensive science research era. Standing on a broader vision, Astroinformatics will act as a sub-discipline of Astronomy to enable data-intensive astronomical science. In the paper, backgrounds and current status of VO research and development are introduced, challenges faced to Astronomy and requirements for Astroinformatics are discussed, activities and achievements from CAS astronomical observatories on e-Science are reviewed, prospects for VO in China is described.