In　this　paper,　a　new　cracked　stiffener　model　for　the　stiffener　with　a　part　through　and　open　crack　is　proposed,　considering　the　compatibility　condition　of　displacements　between　the　plate　and　the　stiffener.　Based　on　the　first-order　shear　deformation　theory,　the　free　vibration　of　stiffened　isotropic　plates　with　cracked　stiffeners　are　investigated　for　the　first　time.　The　description　of　the　crack　parameters　is　based　on　the　continuous　equivalent　bending　stiffness　and　equivalent　depth　of　the　cracked　beam,　and　it　takes　into　consideration　of　shear　deformation,　bending-extensional　coupling　vibration,　and　eccentricity　between　the　stiffeners　and　the　plate.　The　stiffened　plates　with　single　or　multiple　cracked　stiffeners　are　formulated　and　discussed.　The　Ritz　method　with　the　modified　characteristic　functions　is　applied　to　demonstrate　the　effects　of　crack　parameters　(crack　depth　and　location)　coupling　with　the　position　and　number　of　the　cracked　stiffeners　on　the　vibration　frequencies　and　modes　of　the　stiffened　plate.　The　validity　and　accuracy　of　the　present　solutions　are　verified　through　convergence　studies　and　compared　with　the　finite　element　results.