Single　Sign-On　(SSO)　is　an　important　cryptography　mechanism　in　distributed　systems　and　is　implemented　by　many　known　distributed　systems,　such　as　the　famous　Kerberos.　Quantum　cryptography　has　gained　great　successes　and　makes　great　influence　on　traditional　cryptography.　In　this　paper,　we　combines　the　SSO　mechanism　and　quantum　cryptography　together.　A　SSO　solution　under　almost　pure　quantum　cryptography　is　designed.　Through　security　analysis,　we　show　that　this　solution　has　good　security　properties.