with　the　development　of　Internet,　Information　security　is　becoming　more　and　more　important.　Traditional　cryptographic　methods　require　the　user　to　remember　keys,　it　is　not　convenient.　Biometrics　based　cryptographic　key　generation　techniques　generate　cryptographic　keys　from　biometrics　directly.　In　this　paper,　we　propose　a　biometric　cryptosystem　based　on　face　biometrics.　At　encryption　stage,　a　128-dimensional　principal　component　analysis　(PCA)　feature　vector　is　firstly　extracted　from　the　face　image.　And　a　128　bit　binary　vector　is　obtained　by　thresholding.　Then　we　select　the　distinguishable　bits　to　form　biokey　and　the　optimal　bit　order　number　is　saved　in　a　look-up　table.　Furthermore,　an　error-correct-code　(ECC)　is　generated　using　Reed-Solomon　algorithm.　The　message　is　encrypted　using　symmetric　DES　with　bio-key.　In　decryption　phase,　a　128-　dimensional　PCA　features　vector　extracted　from　the　query　face　image.　Then　a　bio-key　is　generated　using　the　look-up　table　generated　at　encryption　stage.　The　final　key　is　obtained　using　both　bio-key　and　Error　correct　code　(ECC).　Finally,　the　symmetric　DES　decryption　algorithm　implemented　to　obtain　message　using　final　key.　The　proposed　scheme　is　tested　using　ORL　face　database,　the　experimental　results　shows　that　our　algorithm　is　effective.　©　2010　IEEE.