The purpose of the current study is to investigate the distribution of mosquitoes and mosquito-borne arboviruses in Gansu Province. The mosquitoes were collected from Jiuquan and Longnan in 2014. 2 833 mosquitoes were collected from Jiuquan, including Aedes dorsalis 2 665 (94.1%), Aedes vexans 150 (5.3%) and Culex pipiens pallens 18 (0.6%). 1 579 mosquitoes were collected from Longnan, including Culex pipiens pallens 1 451 (91.9%) and Anopheles sinensis 128 (8.1%). All mosquitoes were divided into 96 pools and then inoculated onto C6/36, BHK and Vero cells for virus isolation and identification. The results showed that the 96 pools of mosquitoes inoculated on three cells revealed negative cytopathic effect (CPE). Eighteen pools of the mosquito samples showed positive for Liaoning virus (LNV) detection. The genetic evolution analysis of viral nucleotide sequences showed that Liaoning virus in Gansu Province had the closest relationship with the Liaoning virus isolated in Xinjiang Uygur Autonomous Region.