[Objective] The research aimed to study the activity and dynamic changes of phenoloxidase in Locusta migratoria manilensis（Meyen） .[Method] Two enzyme solutions of insect body and hemolymph of Locusta migratoria manilensis（Meyen） were prepared by different extract methods,the activity and dynamic changes of phenoloxidase in different sites were measured.[Result] The phenoloxidase activity in hemolymph was significantly higher than that in body fluid,and the activity in female individuals was higher than that in male individuals.The phenoloxidase activity in body fluid was gradually enhanced with the prolongation of laying time in air.The phenoloxidase activity in hemolymph of adult was also gradually enhanced with the prolongation of time.[Conclusion] Part of phenoloxidase was existed in tissues and cells of Locusta migratoria manilensis（Meyen） participating in insect development and construction,and the other part was existed in hemolymph playing an immunological and defensive role.The stability of phenoloxidase was very strong,which was the effective guarantee for wide adaptation ability and strong immunity of insect.
