Objective To establish a new atomic fluorescence spectrometry for the determination of As,Hg and Se in human gastric and intestinal juice. Methods The KBH4 solution was used as a reducing agent to generate hydrides of As,Se and metallic vapour of Hg from samples. Results The lineal range of the method was 5.00-80.00 ng/ml for As, 0.10-4.00 ng/ml for Hg, 0.50-5.00 ng/ml for Se respectively. The RSD was less than 6.0%. For As, Hg and Se, the limits of detection were 0.20, 0.01, 0.33 ng/ml respectively, the recovery rates were 98.6%-104.4%, 92.0%-104.0%, 98.5%-100.5% respectively. Conclusion The method is simple, rapid and accurate with satisfactory results.