Spirulina was supplemented to Kolar Gold silkworm from the beginingof fifth instars to spinning along with V1 mulberry leaves from 0.25to ten per cent. Supplementation of two per cent concentrationsignificantly recorded shorter larval duration (157.62 hr) and enhancedmature larval weight (44.70 g/10 larvae), amylase activity (0.460 μmol/ml/min), pupal weight(16.89 g/10 pupae),cocoon yield (843.34 g/dfl),cocoon weight (21.13 g/10 cocoon), shell weight (4.15 g/10 shells) ,silk filament length (925.99 m), denier (2.50), fibroin (79.02 %) andlower sericin (20.98 %) over other concentration and water anduntreated control.