Natural enemy insects, including predators and parasitoids, are beneficial organisms that feed upon other agricultural pests. Using natural enemy insects to suppress or prevent outbreak of pests is a key component of integrated pest management strategy. It is safe, effective, and environmentally friendly and can be applied easily to the greenhouses, filed crops and orchards. Rearing and application of natural enemy insects in biocontrol in China have a long history. As early as 1700 years ago, the predator Oecophylla smaragdina has been used for controlling many kinds of citrus pests. Up to now, more than 30 species of natural enemies that can be artificially mass produced and widely used for biological control of many kinds of pests, including caterpillars, aphids, whiteflies, thrips, leaf mites and scales in China. The annual average application area of natural enemies is over 11.34 million hectares. However, with the increasing demand of using natural enemies in biological control programs, the development of natural enemy insect industrialization still face many challenges. It is urgent to explore more effective candidate natural enemies, improve the production efficiency, increase the shelf life of products and enhance the colonization of natural enemy insects after release, and thus facilitate the commercially production and application of natural enemies. This is of great significance for comprehensively promoting the use of green prevention and control techniques for crop diseases and pests, reducing the use of chemical pesticides, ensuing the quality and safety of food and agricultural products, and ultimately promoting sustainable agricultural development.