Abstract: An improved method was established for the detection of Olaquindox in aquatic products.An improved pre-treatment method was used in this study.The samples were extracted with hot water and separated by diatomite and n-Hexane, and the chromatographic parameters were optimized, so detection efficiency was raised significantly.The results showed that the average recoveries at two different samples and four different spiked levels was 77.2%~87.0%, the relative standard deviation of 0.4%~6.3%, the detection limit 10 μg/kg, the limit of quantification 30 μg/kg.A mathematical model of uncertainty evaluation was established.Reliability and test conditions were verified by uncertainty analysis and calculation.Relative uncertainty of this method was less than 8%, which was affected by random effect and calibration curve and recovery.This method is not only simple, sensitive and accurate, but also rapid and cost savings, so it is very suitable for the determination of Olaquindox in aquatic products.This study that uncertainty evaluation is used to verify the detection method is very important.