Biopolymer carboxymethyl tamarind seed kernel polysaccharide (CMTSP) was synthesized by the reaction of tamarind kernel powder (TKP) of Tamarindus indica L. with monochloroacetic acid by an improved method. The synthesis was conducted in presence of sodium hydroxide at optimized conditions of time, temperature, concentrations of TKP, MA, sodium hydroxide. Tamarind seed polysaccharide (TSP) was also extracted from TKP by boiling distilled water. The chemical structure of TKP, TSP and CMTSP were analyzed by the ATRFTIR. When TKP, TSP, and CMTSP’s comparative physico-mechanical properties were examined and compared, CMTSP performed better due to increase in viscosity, water solubility and tensile properties.