In　this　work,　a　portable　immunosensor　was　developed　using　a　personal　glucose　meter　(PGM)　as　the　signal　transducer.　In　this　system,　the　anti-alpha-fetoprotein　(anti-AFP)　is　immobilized　on　the　screen-printed　gold　electrode　(SPGE)　surface.　The　presence　of　a　target　brought　in　the　fixation　of　invertase-anti-AFP　on　anti-AFP　modified　SPGE;　then,　invertase　catalyzed　sucrose　to　glucose,　which　was　detected　using　the　PGM.　The　reading　of　the　PGM　exhibited　a　linear　relationship　with　the　AFP　concentration.　The　detection　limit　is　0.18　ng　mL(-1).　After　one　test,　this　immunosensor　can　be　reused　at　least　5　times　using　an　easy　treatment.　Moreover,　the　assay　results　of　the　clinical　serum　samples　are　satisfactory.