Abstract:The best experimental condition and method that determine oil in wastewater in boat's engine room by fluorescence spectrophotometer is reported. Based on the study of several kinds of fluorescence diagrams of oil in boat's engine room,the λ_exMAX＝310 nm,λ_emMAX＝365 nm are chosen.Its operation curve has the linear range of 0.005～10.0 mg/L; the sample has a standard deviation of 0.002～1.03,CV＜5%,and recovery rate of 94%～106%.