Objective To investigate the diversity of mosquito-borne viruses in Xinjiang , China, and to identify mosquitos-borne viruses of medical importance rapidly .Methods The virus-derived RNAs in mosquitos captured in wild were screened and confirmed by using Illumina deep sequencing approach and reverse transcription PCR , respectively .The alignment analysis was performed by using gene sequences from GenBank.Results One hundred and forty-four Culex Flavivirus ( CxFV, Flavivirus genus, Flaviviridae) specific sequences were identified .The overlapping reads were assembled into 7 uncontinuous viral genomic contigs.The gaps between the contigs were further filled by RT-PCR products, which resulted in reconstruc-tion of viral genomic 5′and 3′terminus (687 nt and 411 nt).Phylogenetic analysis showed that the newly identified CxFV belonged to America/Asian genotype , which specifically clustered into a clade with other CxFV strains from China mainland ,sharing 98.2%-99.5%homologies in nucleotide sequences and 99.5%in amino acids sequences among them .Conclusion Illumina deep sequencing approach was successfully applied to arthropod-borne virus surveillance .The recently emerged Culex Flavivirus was detected for the first time in Xinjiang, China.