Radioactive dsDNA probes were prepared by labeling cDNA fragments of CMV RNA3 partial sequence and the full-length satellite RNA (satRNA) with ³²P, respectively. By using nucleic acid spot hybridization (NASH), relative RNA loading (RRL) of both gemonic and satellite RNAs were quantitatively determined from the systemically infected hosts tissue. At 16～20℃, the radish-derived CMV-R3 containing no satRNA was inoculated on four host plants and examined 15 days, 30 days, and 75 days post inoculation, respectively. The resulting RRL showed a declining trend during the test period. On day 15, the RRL for genomic RNA differed obviously among the hosts in the order of Nicotiana.tobacum＞N.glutinosa＞N.clevelandii＞tomato. Meanwhile, the RRL for the CMV-RS, another radish isolate containing high copies of satRNA, was examined 5 days and 15 days after inoculation on the same hosts with CMV-R3 being included as a non-satRNA control. The RRLs for both genomic RNA and satellite RNA of the CMV-RS displayed a similar host- and time-effect trend. On all the inoculated hosts, the RRL increased from day 5 to day 15 and RRL of CMV-RS for both genomic RNA and satRNA was in the quantitative order of N.tobacum＞N.glutinosa＞Nicandra.physalodesand tomato. At 18～21℃, CMV-HC4, a severe tomato isolate containing a necrosis satRNA, was tested after 5 days, 10 days, and 15 days inoculation on 5 hosts. The RRLs of HC4 genomic and satellite RNAs were under the influence of host and inoculation time. The RRLs for satRNA and genomic RNA were similar but had some degree differences among the hosts. On day 10 post inoculation, the relative amount of both genomic RNA and satRNA was ordered as tomato＞N.glutinosa＞N.tobacum. The results also showed that different CMV isolates have obvious preference among hosts for replication and accumulation of viral RNAs.