Epicoccosorus nematosporus was detected in all 22 counties surveyed, but the frequency of occurrence of fingerprint stem blight disease (FSBD) on Eleocharis kuroguwai caused by the fungus varied with fields and regions. The disease occurred more frequently in mountain areas than in plain areas. E. nematosporus was detected in less than 20% of plain areas such as Gimjae and Milyang, whereas, it occurred in 40-60% of mountain areas such as Sangju and Jangsoo. In Milyang, mean temperature in July to August 1993 ranged from 17 to 27℃ with 14.3 h of dew period. Meanwhile, in the mountain area such as Sangju, Gyeongbook, temperature ranged from 17 to 24℃ with 16.1 h of dew period. Plant mortality was 61% in Milyang and 82% in Sangju. Underground tuber formation was highly suppressed at 16 and 33 tubers per plot in Sangju and Milyang, respectively. In 1992 and 1995, plants infected ranged from 40 to 78% in July to September. This sharply decreased to an average of 15% in 1999.