By use of an oligo(dT) 18 as a reverse transcription primer, polyadenylated RNA viruses CTV and CTLV were detected by RT-PCR. CEVd could be also detected in this way. CEVd is a non-polyadenylated RNA viroid, but there is a fragment rich in A in CEVd sequence. On the bases of uniplex RT-PCR, a multiplex RT-PCR was developed to detect CTV, CEVd and CTLV simultaneously. The results of the multiplex RT-PCR to detect each of the pathogens were consistent with uniplex RT-PCR. The multiplex RT-PCR provides a simple and rapid method for detecting CTV...