Although the polarization properties of Iodine/PVA polarizers are excellent, they are quite susceptible to heat attack under humid conditions at elevated conditions. The research of high-temperature iodine/PVA polarizers leads to extend the applied range of liquid crystal displays, iodine/PVA polarizers containing Co^2＋were studied. The optical and heat-resistant properties were characterized and analyzed. FT-IR spectra indicated that Co^2＋can form the complex with PVA and I , also form more stable one with PVA, H3BO3and I . Boric acid mainly akes the ehromophore of I5^-stabilize resulting from intermoleeular --OH groups cross-linking with B- O bonds. XRD patterns showed that Co^2＋reduces （10 1） interracial spacing and impedes the migration and decomposition of I5^-chromophores. DSC results indicated that heat-proof temperature of iodine polarizing films containing Co^2＋is increased to 109 ℃ from 90 ℃, which is the heat-proof temperature of polarizing films only treating with boric acid solution.