In this contribution, we reported the synthesis of linear organic-inorganic polyurethanes with heptaphenyl polyhedral oligomeric silsesquioxane (POSS) as the side groups. First, a novel POSS diol was synthesized; then the POSS diol as well as 1,4-butanediol was used as the chain extender to obtain the organic-inorganic polyurethanes with various content of POSS. Gel permeation chromatography (GPC) showed that the high-molecular-weight products were obtained. Small angel X-ray scattering (SAXS) and transmission electron microscopy (TEM) showed that in the organic-inorganic polyurethanes the spherical POSS microdomains with the size of 10-20 nm were formed via POSS-POSS interactions. Compared to plain polyurethane, the organic-inorganic polyurethanes displayed increased glass transition temperatures. Owing to the formation of POSS-POSS interactions, the mechanical properties of the polyurethanes were significantly improved in terms of Young's modulus and tensile strength. More importantly, the organic-inorganic polyurethanes displayed good shape memory properties, which was in marked contrast to plain polyurethane. The improved shape memory properties are attributable to the formation of the POSS microdomains via POSS-POSS interactions, which promoted the inter-chain interactions.