Pheromones play an important role in chemical communication among organisms.A number of pheromones have been identified with many of them being chiral and non-racemic.Extensive studies on the relationships between stereochemistry and bioactivity of insect pheromones confirm the key role played by the stereochemistry in the bioactivity of the pheromones.In addition, the minus amounts of pheromones available from natural sources prevent a profound bio-and ecological study.Therefore the enantioselective synthesis constitutes an important tool, not only for the establishment of the absolute configuration of the naturally occurring pheromones, and the clarification of the relationship between absolute configuration and the bioactivity of the chiral pheromones, but also for the pests monitoring and control.In this talk,we shall present new methods for the asymmetric synthesis of pheromones of pine sawflies (1, 2),1and the pheromone components of the Fall Webworm Moth (3, 4),2 as well as some alkaloidal pheromones.