Phellinone, a new furanone derivative, has been isolated from the stem-cooked rice culture broth of Phellinus linteus KT&GPL-2. Phellinone was purified by consecutive solvet partition, silica gel, preparative TLC and preparative HPLC. The structure of phellinone was assigned as a furanone derivative on the basis of various spectroscopic analyses, including Mass and NMR spectroscopies. Its molecular weight and formula were found to be 248 and $C_{15}H_{20}O_{3}$, respectively, and showed antimicrobial activity against Bacillus subtilis IAM 1090.