Abstract:The highly conserved DNAs of Equine herpesvirus 1(EHV1), Equine arteritis virus(EAV), Equine influenza virus(EIV), Equine infectious anaemia virus (EIAV) and Eastern equine encephalomyelitis virus (EEEV) were acquired by molecular cloning, and then spotted on the treated glass slides as the diagnostic gene-chip. And the cDNAs reverse-transcripted from RNAs of samples were labeled with Cy5 fluorescence as probes. Following specific hybridization of deposited gene chip and labeled probes, fluorescence signals were scanned by laser scanner and the obtained image was analyzed by QiamtArray software with the digital computer. The results showed that the prepared gene chip could detect and distinguish the five equine viruses. And its sensitivity was about 25 copies of viral genomes. The hybridization specificity was confirmed by the presence of red fluorescence signals on the corresponding sites with samples from the five relevant viruses in horses and by the absence of positive signals with the specimens from irrelevant viruses in other animals. Peripheral blood leucocyte (PBL) from some seropositive horses of post-arrival quarantine was negative by virus isolation but positive for EHV1 and EAV by gene chip. The evidence suggests that gene chip, which is quick, specific, sensitive, and reliable, can provide a practical alternative to screen and quarantine a large number of samples within a very short period of time.