The　terrorism　threat　which　is　conducted　by　international　terrorists　who　possess　forged　identities　and　passports　becomes　more　and　more　serious　and　imminent.　Traditional　methods　and　techniques　of　preventing　passport　from　forgery　are　not　effectual　enough.　This　paper　proposes　a　passport　anti-forgery　system　based　on　the　public　key　signature　scheme　RSA.　The　anti-forgery　system　contains　four　modules:　the　passport　dada　edit　module,　passport　key　production　module,　passport　signature　module　and　passport　verification　module.　A　private　key　used　for　signing　is　preserved　separately　by　an　authorized　issue　official,　and　a　public　key　used　for　verifying　is　stored　into　a　database　which　a　web　server　can　access.　In　this　way,　the　anti-forgery　property　of　a　passport　is　equivalent　to　the　security　of　an　adopted　public　key　signature　scheme,　and　the　passport　is　bound　with　its　issue　authority　tightly.