Nanoparticles are defined as particulate dispersions or solid particles with a size in the range of 10-1000nm. The main use of the polymeric nanoparticles was to deliver the drug to the appropriate site and also to achieve the effective, controlled, protective drug delivery without any toxic side effects. By using this fenugreek seed polymer Diltiazem HCl which has short half-life was successfully incorporated to retard the drug release and prevent the drug degradation. The present research work revealed the use of fenugreek seed polymer as an effective rate controlling polymer in preparation of polymeric nanoparticles by desolvation method. From this study we concluded that the use of natural polymers for the preparation of nanoparticles is beneficial than toxic synthetic polymers. Keywords: Formulation, Characterization, Anti-Hypertensive Drug, Nano Particle.