Silk proteins composed of many amino acid residues. They were linked with peptide bonds. Eri silk protein by basic hydrolysis gave higher tyrosinase inhibition activity with the IC50 value of 10.43 mg/ml which was 100 times of vitamin C. However, the highest free radical scavenging activity was observed in Eri silk protein prepared from basic hydrolysis process with the lowest SC50 value of 11.67 mg/ml which was 100 times of the standard vitamin C