Abstract: PAGES is a core project of IGBP,which will covert wenty years from 1991 to 2010 AD.CLIVAR,which was iniciated in 1996 and will last to 2010 AD,is a new sub-project of WCRP.Scientific intersection problems between these two projects are outlined as following:(1) dynamics of low-latitude climate change,(2) global ocean thermo haline variability,(3) regional-toglobal-scale hydrologic variability,(4) dynamics of abruptcl imatechange,(5) climate model evaluation and improvement,and (6) climate change detection.