Plant derived products provide defense to plants against herbivore insects by acting as antifeedant, growth regulators, toxins andmodulate the activity of various enzyme. Additionally botanicals can also effect the immune system of insects. The present work reveals the impact of secondary metabolites of Alpinia galanga, a me-dicinal plant on humoral immune response of Spodoptera litura (Fab.). Addition of ethyl acetate extract and purified compounds viz. galangin and 1’-acetoxychavicol acetate induced the activity of phenoloxidase. Fluctuation in lyso-zyme activity was observed due to ethyl acetate extract. Although higher concentration of galangin induced the lyso-zyme level, but 1’-acetoxychavicol acetate did notsignificantly influence in enzyme level. Understanding the effect of biopesticides in immune response would help to design effective strategies for the control of insect pests.