In April 2021, symptoms of green-yellow mosaic and mottling were observed on leaves of Calotropis gigantea plants. Incidence of the symptoms observed and the unit surveyed 90% of plants were symptomatic in 3 fields around the city of Honghe, Yunnan Province, China. Leaf samples were collected from five symptomatic plants. Transmission electron microscopy observations of crude sap showed numerous isometric particles characteristics of cucumoviruses with a diameter of 20∼30 nm in symptomatic leaves of Calotropis gigantea. Total RNA was extracted from symptomatic leaves (White et al. 2008) and tested by RT-PCR with specific primers designed in a segment of coat protein gene (nucleotides 1332–1819) of cucumber mosaic virus (CMV): CMV-F 5’-CGTCCTACTATTAACCACCC-3’ and CMV-R 5’-ACCAACTCATCCGTCTCG-3’ (GenBank accession number JX993914.1). A 487-bp DNA fragment was obtained, cloned into the pMD18-Tvector (Takara) and sequenced. BLAST analysis revealed 99% identity at the nucleotide level between the CMV sequences from Calotropis gigantea and CMV isolate YV1059 from Yunnan, China (MH807716.1). CMV was mechanically inoculated from Calotropis gigantean leaves onto Nicotiana tabacum, which showed foliar distortion and tested positive for CMV by RT-PCR with the same primer set. To the best of our knowledge, this is the first report of CMV infected Calotropis gigantea in the world.