[Liu Hui-Hui] Henan Univ Sci & Technol, Dept Phys, Luoyang 471003, Peoples R China
; [Liu Hui-Hui
; Chen Jiang-Chuan] Chinese Acad Sci, Inst High Energy Phys, Beijing 100049, Peoples R China
; [Zhang Xiao-Fei] Binzhou Coll, Dept Phys & Elect Sci, Binzhou 256600, Peoples R China
Using a data sample of about 33 pb(-1) collected at and around root s = 3.773 GeV with the BES-II detector at the BEPC, we have directly measured the branching fraction for inclusive semimuonic decay of neutral D mesons to be BF (D(0) -> mu(+)X) = ( 7.2 +/- 1.5 +/- 0.8)%.