Abstract: One virus isolated from Dahlia pinnata Cav. grown in Xiamen area was identified as an isolate of Cucumber mosaic cucumouirus based on its biological characteristic, particle morphology and serology of the virus isolate. The virus isolate could infect 35 species (or varieties ) of 9 families from 39 species (or varieties ) of 11 tested families. The thermal inactivation point for the virus isolate was 50-55℃; the dilution end point was 10-3 -10-4 and the longevity was 24-48 h. The electron microscopic examination showed the purified virus particle preparations was isometric particles of about 28-30nm in diameter. The virus isolate had strong positive reaction to monoclonal antibodies of CMV by enzyme-linked immunosorhbent assay, and no reaction to monoclonal antibodies of TMV, SqMV, TRSV, TAV, PFWV.