The present investigation was carried out to characterize starches, particle size, morphology index and structural properties from velvet bean seed powder. Structural characteristics of starch extracted from these nano sized seed powder was evaluated using X-ray diffraction (XRD) and analyzed particles size, morphology, and degree of Crystallinity. From our XRD analysis, starch presented a C-type XRD pattern and crystallite size of 38.26?. The particle size was found to be 15 to 41 nm. Morphology index (MI) ranged from 0.5 to 0.73. It is observed that MI has direct relationship with particle size and indirect relationship with specific surface area.The morphology and particle size was confirmed by XRD, Transmission Electron microscopy (TEM) which showed formation of well-dispersed gold nanoparticles in the range of 14 to 43 nm with monodisperse in nature. These starch nanocrystals could be potential precursors to nanocomposites and nanoparticle-based copolymers.