Abstract: Yellow vein clearing disease caused by Citrus yellow vein clearing virus（CYVCV）was first found in Eureka lemon in Ruili，Yunnan in 2009，and it was observed in several citrus-growing areas of China in recent years. In order to establish the reverse transcription loop-mediated isothermal amplification（RT-LAMP）assay，primers were designed from the conserved region in the coat protein（CP）gene identified by multiple sequence alignment of CP gene sequences of CYVCV available in GenBank，and its reaction conditions was optimized. CYVCV was identified by RT-LAMP while Citrus tristeza virus（CTV），Citrus psorosis virus（CPV），Citrus exocortis viroid（CEVd），Satsuma dwarf virus（SDV），Citrus tatter leaf virus（CTLV）and Huanglongbing（HLB）were not amplified by the RT-LAMP assay. Sensitivity of the RT-LAMP assay was 10-fold higher than RT-PCR. The positive rate of 30 samples from Yunnan by using the RT-LAMP was 63.33%，the same as RT-PCR，suggesting the RT-LAMP assay worked as well as RT-PCR. In addition，amplification products were able to detect by visual inspection using SYBR GreenⅠand there is no need for gel electrophoresis. Hence，this RT-LAMP assay is a specific，sensitive and rapid method for detecting CYVCV.

Key words: Citrus yellow vein clearing virus, RT-LAMP, detection