Abstract: Insects keep comunication with environment and make behavioral and physiological response to chemical and physical signals in enviroment to live in it. Agricultural and forest and other resources may be protected effectively through manipulating pests behaviors by utilizing these signals. From the application point of view, semiochemicals are classified into attractants, repellents, stimulants and delerrents. Brief discription about principles, methods and results of applying these signals are given with examples including those already successfully used in practices and those still in research phase. Perspectives and development of manipulating pest behavior mainly with semiochemicals to control them are discussed.