In　this　paper,　the　buckling　and　free　vibration　of　a　Mindlin　plate　with　a　side　crack　are　presented　considering　a　uniaxial　in-plane　compressive　or　tensile　load.　The　side　crack　is　through　the　thickness　of　the　plate.　In　the　Ritz　method,　a　series　of　corner　functions　are　incorporated　into　the　admissible　functions　which　consist　of　the　modified　characteristic　functions.　With　this　treatment,　one　can　describe　the　singularity　in　stress　near　the　tip　of　the　crack　as　well　as　the　discontinuities　in　both　displacement　and　bending　rotations　across　the　crack.　The　buckling　loads　and　natural　frequencies　are　solved　through　eigenvalue　problems　considering　the　existence　of　the　crack.　The　effects　of　location,　length　and　orientation　of　the　crack　on　the　buckling　and　free　vibration　of　the　loaded　plate　are　demonstrated.　The　coupling　effect　of　the　crack　and　the　in-plane　load　on　the　vibrational　characteristics　of　the　plate　is　analyzed　with　varying　parameters.　It　is　shown　that　the　influences　of　the　tensile　and　compressive　preloads　are　enhanced　by　the　crack,　and　the　tensile　preload　can　cause　the　low-order　frequency　to　increase　with　the　growing　crack.