A series of optically active polyamidos containing di-O-methyl-L-tartaryl moieties in the main chain were synthesized by polycondensation of di-O-methyl-L-tartaryl chloride 5 with diamines and characterized by gel permeation chromatography, UV-vis, circular dichroism (CD), IR, and NMR spectroscopies. The polycondensation reaction could be carried out under mild conditions and the reaction time was short (2-3 h). The key monomer 5 prepared from L-tartaric acid via esterification, etherification, hydrolysis, and chlorination was easily purified by vacuum sublimation. These polyamides with number average molecular weights ranging from 14,000 to 35,000, displayed large optical activity in dimethyl sulfoxide solution, and their specific optical rotations oscillated between 87.2 degrees and 210.7 degrees depending on the structures of the diamines. The glass transition temperatures of these polyamides were in the range of 106-191 degrees C, and the 10% mass loss occurred at temperature above 300 degrees C. The polyamides derived from aromatic diamines exhibited higher T-g and thermal stability than those derived from aliphatic diamines. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 117: 3558-3567, 2010