In this paper, the author gave a brief review on the meaning and background involving the growth of chemical ecology. Semichemicals which might be developed as insect control techniques incorporating in IPM program were described. The relevant semichemicals were grouped under separate topics including intraspecific semiochemicals, or pheromones (sex pheromones, alarm pheromones, and epidiectic pheromones), and interspecific semiochemicals, or allelochemics (allomones of Plant origin, and kairomones favoring natural enemies). Here, the author dealt with those of practical aspects only. The prospects of chemical ecology in insect pest management were also proposed.