Cloud　computing　is　a　hot　topic　of　current　research,　for　anonymous　authentication　is　required　in　many　applications　scenarios　of　e-business　based　on　cloud　computing,　users　do　not　want　to　expose　their　identity,　users　just　hope　that　service　providers　know　they　are　legitimate　users　like,　for　this　application,　this　paper　presents　a　anonymous　authentication　scheme　without　certificate,　which　this　scheme　avoids　the　issues　how　to　revocation　public　key　certificate　and　the　escrow　problem　of　key,　and　then　the　security　of　the　scheme　is　analyzed.