Invertebrate, which lack adaptive immune system, have developed defence mechanisms that respond against antigens present on the surface of potential pathogens. The defence mechanisms of invertebrate depend on the innate immune system that is activated when pattern recognition proteins (PRPs) recognize the signature molecules of microbes which, in turn, activate cellular and humoral effector mechanisms to destroy invading pathogens. β-1,3-glucan binding protein (βGBP) is a crucial pattern recognition protein, that distinctively binds with β-1,3-glucan (βG), a surface marker of fungal cell wall. βGBP triggers innate immunity by activating prophenoloxidase cascade, and eliminate the pathogenic invasion. This review analyses the functional role of βGBP in the specific recognition of carbohydrate containing molecule βG present at the surface of bacteria and fungi.