Objective:To explore arboviruses carried by midges in Shizong county, Yunnan province.Methods:A total of 74 batches of 3705 midges collected from Shizong county, Yunnan province in July 2013 were detected by RT-PCR method, and then the amplified bands were cloned and sequenced. MegAlign in DNAStar software was used for homology analysis, MEGAX software ALIGN for sequence alignment and genetic evolution analysis based on Maximum Likelihood (ML) method .Results:Among 74 batches of midge samples collected in Yunnan province, 600 bp electrophoresis bands were amplified in 3 batches: SZC33, SZC42 and SZ625C8-2, while no electrophoresis bands were amplified in the other 71 batches of midge samples. After cloning, we selected 5 clones for sequencing, among which the 5 clones of sample SZC42 obtained 589 nt sequences. BLASTx comparison showed that the 5 cloned sequences of SZC42 had the highest amino acid homology(69%) with the non-structural protein gene of Culex bastrovirus-like(CAVL) virus found in mosquitoes collected in the United States, which was designated as Midge bastrovirus-like virus (MAVL). The result of genetic evolution analysis showed that MAVL detected in midges formed a single evolutionary branch, and it’s homology of nucleotides and amino acids with other astrovirus(AV) was less than 71.4%. Further analysis revealed that MAVL had a close genetic evolution relationship with CAVL (NC_040647) detected in American mosquitoes, AV (MF042208) detected in Brazilian sewage and AV (NC_032426) detected from Vietnamese bats, and the homology was 61.4%-66.2% (nt) and 67.7%-71.4% (aa), while far genetic evolution and low homology of nucleotides and amino acids with other AV sirains.Conclusions:A new astrovirus (MAVL) was detected in midges collected from Shizong county, Yunnan province in 2013.