Astronomy　research　has　entered　an　increasingly　data-intensive,　or　“big　data”　era.　Exponential　growth　in　the　size　of　astronomical　archives　brings　with　it　completely　new　requirements　and　challenges　for　data　storage,　computing　power,　networks,　software,　algorithms,　and　even　research　methods.　Astronomers　and　experts　in　information　and　computation　technology　(ICT)　are　working　together　to　simplify　knowledge　discovery　within　these　massive　data　sets.　Worldwide　astronomical　archives　are　connected　through　the　virtual　observatory　(VO)　framework,　which　provides　interoperability　standards　and　services　that　have　allowed　the　creation　of　a　global　astronomical　data　grid.　Astroinformatics,　a　bridge　between　astronomy　and　ICT　and　applied　computer　science,　aims　to　engage　a　broader　community　of　researchers　both　as　contributors　to　and　as　consumers　of　the　new　methodology　for　data-intensive　astronomy,　thus　building　upon　the　data-grid　foudations　established　by　the　VO　framework.　Data　mining　(DM),　knowledge　discovery　in　databases　(KDD),　machine　learning,　and　visualization　techniques　have　become　a　necessity.　In　this　paper,　the　challenges　facing　modern　astronomical　research　are　briefly　described,　the　concepts　underlying　the　VO　and　astroinformatics　and　the　latest　progress　in　these　fields　are　introduced,　and　the　need　for　DM　and　KDD　techniques　in　astronomy　is　discussed.　©　2015,　Science　Press.　All　right　reserved.