To bring this project in a short touch down, for the first time, a series of novel chiral biodegradable polyesterimides having different natural amino acids in the main chain as well as in the side chain were synthesized by direct polycondensation reactions. Structural modifications designed is done to improve solubility of the polymers through the disturb regularity and chain packing. Thus, the new aromatic diol and four aromatic chiral diacid monomers were synthesized in several steps. Chemical structure of these monomers was confirmed by FT-IR, 1 H-NMR, 13 C-NMR spectroscopes, elemental analysis and specific rotation techniques. Direct step-growth polymerization of these monomers for producing polyesterimides was carried out in the presence of tosyl chloride, DMF and pyridine as condensing agent under conventional heating condition. The optically active polyesterimides were obtained with good yield and moderate inherent viscosity ranging from 0.33 to 0.35 dL/g and showed good thermal stability. The presence of amino acid in the polyesterimides architecture, not only cause to be used as optically materials but also makes the polymers as a biocompatible and biodegradable compound. Biodegradability of polymers was investigated by exposing them to a biological environment, includes the biological agents responsible for the deterioration of polymeric substances. Biological agents such as bacteria, fungi and their enzymes consume polymer as food source so that its original form disappears. During degradation samples are removed for assessment of changes by light microscopy to assess surface damage and to look for the presence and nature of microbial growth. All of information improve that these new polyester are biodegradable. In the second part of the project, the new nanocomposites drived from synthesized polyesterimide containing different amount of titanium dioxide as nanoparticle were synthesized. To achieve good dispersity of nanoparticle in the polymer matrix ?-amino propyle three ethoxy silicate was used as a coupling agent for copulating nanoparticle. The presence of nanoparticle and its effect on polymer was confirmed by FT-IR, XRD, UV spectrometer and TGA techniques. These nanocomposite showed higher thermally stable than polyesterimides and also their SEM show the homogeny compound.