Amylase is one of the important digestive enzymes involved in the hydrolysis of starch. Silver nanoparticles are proven to be an effective catalytic material for various applications due to their excellent optical and electronic properties. A laboratory experiment is carried out at the Department of Nano Science and Technology, Tamil Nadu Agricultural University to study the catalytic activity of hydrolytic enzyme ?- amylase and synthesized silver nanoparticles on the degradation process of starch stored in the Cyperus rotundus tubers. The silver nanoparticles are synthesized by soluble starch reducing silver nitrate to silver atoms and were characterized by UV-Vis spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR) and Transmission Electron Microscope (TEM). ?-Amylase at the concentration of 500 ppm/kg of tubers recorded higher rate of starch degradation of C. rotundus tubers. It recorded 21.76 per cent of starch degradation over control. Silver nanoparticles at the concentration of 2.5 g/kg of tubers recorded 7.3 per cent of starch degradation over control. ?-Amylase + silver nanoparticles at the concentration of 500 ppm + 2.5 g/kg of tubers, respectively recorded 25.31 per cent of starch degradation over control. Starch synthesized silver nanoparticles showed an increased rate of reaction with ?-amylase. The degradation of starch digestion kinetics in the presence of silver nanoparticles rapidly produced larger amounts of reducing sugars. The nanoparticles enhance the basal ?-amylase activity leads to effective starch degradation.