Bi-substituted dysprosium iron garnet films were prepared by sol-gel process, and were annealed for crystallization. The crystallographic structures of garnet films annealed at different temperatures were analyzed by XRD, the film annealed at 650℃ was polycrystalline garnet with no preferred orientation and no impurity crystalline phase. Magnetic and magnetooptical properties were investigated, the film had magnetic anisotropy perpendicular to the film plane, and exhibited strong coercivity of 1100～1600 Oe and high squareness. These films had large figures of merit applicable to magneto-optic storage,with 2 deg. at λ=430 nm and 1.5 deg. at λ=520 nm respectively.