Abstract: To identify viral pathogens associated with apricot tree decline and leaf chlorosis，we conducted a high-throughput sequencing of the small interfering RNA（siRNA）of the leaf samples. Based on the siRNA sequences，potential viral pathogens were detected，including the Asian prunus virus（APV）1 and APV 3. To confirm the existence of the viruses in the symptomatic samples，ten leaf samples were collected and tested by reverse transcription-polymerase chain reaction. The result showed that the infected number of APV1 and APV3 was 3 and 4，respectively. Moreover，cloning and phylogenetic analyses were carried out on the coat protein（CP）of the APV1 and APV3. The CP fragments of the APV1 in the three samples were identical to each other in size of 653 bp，while the CP fragments of the APV3 in the four samples were 1 031 or 1 032 bp in size. Pairwise comparison analysis revealed that the nucleotide sequence identities between the three APV1 isolates were from 99.2% to 99.8%，and they shared the nucleotide sequence identities of 44.0% to 99.8% with other published APV1 isolates in NCBI. The four APV3 have nucleotide sequence identities from 78.5% to 99.5% between each other，and they shared nucleotide sequence identities of 44.7% to 99.5% to those published in NCBI.

Key words: apricot, decline and leaf chlorosis disease, Asian prunus virus 1, Asian prunus virus 3, siRNA