We first time prepared main-chain type cage octasilsesquioxane (T-8) containing coordination polymers based on transition metal complexes with a bis-Schiff base T-8 ligand (bis-SA-T-8), which was prepared from para-bis(3-aminopropyl)hexaisobutyl-substituted T-8 cage (bis-T-8) with salicylaldehyde. A mono-Schiff base T-8 ligand (SA-T-8) was prepared from 3-aminopropylheptaisobutyl-substituted T-8 cage (mono-T-8) with salicylaldehyde. Coordination of bis-SA-T-8 with Cu2+ and Zn2+ in a solution as well as the film state was confirmed by the d-d transition appearing as broad shoulder on the longer wavelength at around 600 nm and the fluorescence at around 440-470 nm, respectively. The resulting metallosupramolecular polymers gave optically transparent films in the visible region by a casting method. However, opaque green and whitish films were obtained in the case of the Cu2+ and Zn2+ complexes with SA-T-8, respectively. The thermal stabilities of the metallosupramolecular polymers were higher than those of the corresponding metal complexes of SA-T-8. (c) 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019