Service　discovery　is　very　useful　in　pervasive　computing　environments.　A　service　discovery　architecture　based　on　anycast　is　proposed.　A　well-known　anycast　address　is　defined　first,　which　stands　for　a　group　of　directory　servers　supporting　service　discovery.　Each　node　in　pervasive　environment　determines　whether　it　is　qualified　to　be　a　directory　server　in　accordance　with　its　capability,　such　as　its　memory,　energy,　or　location　stability.　Qualified　node　announces　that　it　serves　the　well-known　anycast　address　and　then　begins　to　listen　and　cache　service　register　messages　from　other　nodes.　A　node　supplying　a　service　sends　register　messages　to　the　well-known　anycast　address.　The　message　is　routed　the　nearest　one　of　directory　servers　by　an　underlying　anycast　routing　protocol.　When　a　node　wants　to　get　some　service　information,　it　sends　query　messages　to　the　anycast　address,　too.　The　message　is　also　routed　to　the　nearest　directory.　The　directory　replies　in　accordance　with　the　information　cached　or　obtained　from　other　directories.　With　anycast,　network　load　caused　by　service　discovery　is　reduced　dramatically,　which　results　in　scalability.　The　architecture　is　fully　distributed,　which　does　not　depend　on　any　central　point　Therefore　the　architecture　is　a　good　candidate　solution　for　service　discovery　in　pervasive　environment.