elimination of neomycin sulfate were investigated after single oral administration() in tilapia (Genetically improved farmed tilapia, GIFT) at The concentration of neomycin sulfate in tissues of tilapia were determined by time data of neomycin sulfate of plasma was best defined as two-compartmental open model. The maximal concentration, peak time and elimination half-life of plasma were 9.138 μg·mL^{, 10.998 h and 25.776 4 h, respectively.The elimination speed from fast to slow were muscle, liver, kidney with the elimination half-life of 31.802 h,34.917 h, 45.175 h, respectively. According to the People’s Republic of China Announcement No.235, the maximum residue limit of 0.5 mg·kg in muscle of avian, the withdrawal period should not be less than 6 d under this experiment condition.}