Crustacean immune response mainly based on innate immune effector cells or hemocytes and hemolymph. Such immunocytes show diverse functional activities including aggregation, adhesion, coagulation, phagocytosis, degranulation, generation of cytotoxic agents and hemolymph consists of different proteins and enzymes in inactive forms to get active to protect the crustaceans from invading pathogens and toxins of unknown chemical nature within hostile biounsafe environment. Due to continuous struggle against environmental adversities and potential enemies, crustaceans get physically wounded in their natural habitat frequently. Animals physiologically respond to external injury and rapid sealing of wound at the exoskeletal site is required to prevent the loss of hemolymph and minimization of opportunistic invasion of pathogens. So continuous source of fresh hemocyte production is necessary to overcome such situation. Hematopoietic tissue is the organ of production of new hemocytes which was reported by various scientists in different parts of crustaceans. Present book provide a baseline information concerning the relation between wound repair and hematopoiesis of blood cell of Crustacea.