This　paper　addresses　discrete　subspace　multiwindow　Gabor　analysis.　Such　a　scenario　can　model　many　practical　signals　and　has　potential　applications　in　signal　processing.　In　this　paper,　using　a　suitable　Zak　transform　matrix　we　characterize　discrete　subspace　mixed　multi-window　Gabor　frames　(Riesz　bases　and　orthonormal　bases)　and　their　duals　with　Gabor　structure.　From　this　characterization,　we　can　easily　obtain　frames　by　designing　Zak　transform　matrices.　In　particular,　for　usual　multi-window　Gabor　frames　(i.e.,　all　windows　have　the　same　time-frequency　shifts),　we　characterize　the　uniqueness　of　Gabor　dual　of　type　I　(type　II)　and　also　give　a　class　of　examples　of　Gabor　frames　and　an　explicit　expression　of　their　Gabor　duals　of　type　I　(type　II).