Abstract: Flour and rice are important staple food in most provinces in Northwest China,and they are susceptible to be infected and damaged by stored grain insects in the course of processing,therefore,it is important to know the insect species in grain processing factories for pest management during grain storage.We investigated the insect fauna in 33 flour mills and 35 rice mills of 5 provinces in 3 grain storage ecological regions in China (cold and dry grain storage region,low-temperature dry grain storage region,medium-temperature dry grain storage region).Through arrangement and preliminary systematic research,the results showed that 61 species of insects which belonged to 26 families of 5 orders were found.There were 19 families of Coleoptera,4 families of Lepidoptera,one family of Thysanura and Hymenoptera;and insects of Arachnoidea belonged to one family of Pseudoscorpionida.