Barley yellow mosaic virus (BaYMV) is transmitted by a root-inhabiting Polymyxa graminis (P. graminis) and thus the disease is called “soil-borne”. In this study, the presence of P. graminis was confirmed by PCR test based on specific sequences of P. graminis type Ⅰ (P. graminis f. sp. temperata) Internal Transcribed Spacer (ITS). P. graminis was detected in the BaYMV infected soil and root of barley plants. The monitoring of P. graminis was conducted in March 2015 in 8 korean provinces. It was detected in the soil of all collected regions. This is the first report on a P. graminis a survey of Korea.