Natural enemies play an important role in limiting the densities of potential pests. Yancheng, Jiangsu is located in the eastern coast of China, and has great potential for land utilization. Yancheng is an important crop production area in China. It is significant to explore and utilize natural enemy resources actively in such a large agricultural city. The present work started in 2018 to clarify biodiversity of local natural enemies, the structure of dominant populations and their spatial and temporal dynamics in Yancheng. The investigation used the plate beat method, the Malay's net trap method,etc to conduct long-term investigation and collection of the types and numbers of predatory natural enemies. Major natural enemies surveyed include ladybug, hoverfly, lacewing, spider, etc. Data on natural enemy species, density, and pictures and habitat information were provided. The establishment and sharing of this dataset provided basis to well understand predacious natural enemy resources in Yancheng area. It can be used to study population dynamics and occurrence pattern of local natural enemy, to evaluate and utilize dominant species, and to promote local green pest control technologies.