The chlorinated alkyds were synthesized by the direct chlorination of the soybean oil alkyds of 55% oil length in carbon tetrachloride. Five samples of chlorinated alkyds, varying in the chlorine content from 11.8 to 50.8%, were synthesized in order to study the effect of chlorine; It was confirmed through IR spectroscopy that chlorine enters only into the aliphatic portion of the alkyd molecule by addition and substitution reactions. Thermal stability of the chlorinated alkyds was found to increase with the chlorine content. In addition to general characterization, the mechanical and chemical film properties of the unchlorinated and chlorinated soybean alkyds were also appraised simultaneously which revealed that, in general, the chlorinated soybean alkyds possessed superior film forming properties as compared to the unchlorinated ones except in terms of flexibility and solvent resistance.