One hundred and seventy six maize samples showing dwarf mosaic symptoms from 15 sites in 12 provinces in China were collected and detected with Sugarcane mosaic virus (SCMV)monoclonal antibody 2B5 by indirect ELISA. All the samples gave a positive signal. The samples were then analyzed by immunocapture reverse-transcription PCR (IC-RT-PCR) with primers specific for SCMV, Maize dwarf mosaic virus (MDMV), Sorghum mosaic virus (SrMV), and Johnsongrass mosaic virus (JGMV), respectively. Only primers specific for SCMV gave PCR products in all of the tested samples. The results showed that SCMV was probably the only potyvirus infecting maize in China. In addition, the nucleotide sequence covering the core region of coat protein (CP)of SCMV isolates from Gansu, Sichuan, and Yunnan were determined, and the pathogenicity of SCMV isolates Zhejiang(ZJ)and Gansu(GS)was tested on 13 maize cultivars.