This　paper　addresses　vector-valued　subspace　Gabor　frames　with　rational　time-frequency　product.　By　introduction　of　a　suitable　Zak　transform　matrix,　we　characterize　vector-valued　subspace　Gabor　frames,　Riesz　bases　and　orthonormal　bases.　We　characterize　the　uniqueness　of　Gabor　duals　of　type　I　and　type　II.　Using　the　uniqueness　results,　we　extend　the　classical　Balian-Low　theorem　to　vector-valued　subspace　Gabor　frames.　We　also　point　out　Ron-Shen　duality　principe　does　not　hold　for　a　general　vector-valued　subspace　Gabor　frame.