(, one of the most toxic natural neurotoxins found in several kinds of fishery productscause TTX poisoning. Therefore, detection methods for routine analysis of TTX should be developed. We found that TTX could be converted into a new compound with fluorescence properties by reaction with sodium bromate (NaBrO) and urea. The reaction was sensitive to the acidity level of the solution and the pH value needed to be strictly controlled between 11.611.9. The fluorescence scanning spectrum showed the fluorescent compound maximum excitation wavelength of 233 nm and emission wavelength of 370 nmwas not the product of alkaline degradation (quinazoline). Hence, a new type of fluorescence detection method was developed for identifying TTX in aquatic products. After reaction with NaBrO0.09 mol/L10Na₂CO₃the TTX derivative solution was neutralized with 15% phosphoric acid and then detected by reverse-phase high-performance liquid chromatography with a fluorescence detector. The result was quantified by the standard addition method. The detection limit was 20 μg/kg and the relative standard deviation was 0.44%7.25%. The method was specific, accurate, and sensitive, and can be used for identification of TTX determination.