Recent advances in the studies of acetylcholinesterase (AChE, EC 3.1.1.7) genes from insects were reviewed. The gene structure, including ten extrons of insect AChE gene (ace), was discussed. All the ace genes reported from insects were summed up, and the phylogenetic tree was constructed based on the reported complete sequences of ace genes from insects. The ace structure characteristics, the functional sites of ace genes, the effect of ace mutation(s) on insecticide resistance and their relationships were also discussed. Finally, the problems and prospects in the studies of insect ace were analyzed.