|| Dot-immunobinding assay (DIA) on nitrocellulose membranes and rapid immunofilter paper assay (RIPA) were examind for their usefulness in the detection of cymbidium mosaic virus (CyMV) in orchids. The minimum detection levels of CyMV by these methods were 100 ng/ml in purified preparations and at 10-4 dilution of extracts from infected leaves of orchids could be detected by these methods. Although DIA took 5 to 6 hours for the detection of the virus, it was reliable method for diagnosis of a large-number of samples. On the other hand, RIPA, which enabled detection of CyMV within a few minutes with sensitivity similar to that of DIA, will be suitable as a rapid and handy tool for virus disease diagnosis in orchids. Moreover, by RIPA, we could detect CyMV and odontoglossum ringspot virus (ORSV) simultaneously form doubly infected plant.