A series of new polyimides containing alicyclic units and alkyloxy side chains were prepared from 9,10-dialkyloxy-1,2,3,4,5,6,7,8-octahydro-2,3,6,7-anthracenetetracarboxylic 2,3:6,7-dianhydrides and various aromatic diamines. Their physical properties and structures were investigated. Polymers were obtained with inherent viscosities of 0.24-0.53 dL/g. In comparison with the aromatic polyimides, most polymers were readily soluble in common organic solvent such as N-methylpyrrolidone and m-cresol. These polymers had glass-transition temperatures between 111 and 296 degreesC depending on the structure of the repeating unit and 10% weight-loss temperatures of 418-477 degreesC in nitrogen. Wide-angle X-ray diffractometry for as-polymerized samples revealed very low crystallinity and layered structures, which were better developed in the polymers with longer side chains.