A novel method for highly sensitive detection of acetylcholine in royal jelly was proposed by using CE coupled with electrogenerated chemiluminescence (ECL). Acetylcholine, which could not react with Tris(2,2'-bipyridine)ruthenium(II) to strengthen its ECL signals, decomposed into trimethylamine and strengthened the ECL signals sharply when it was heated to its melting point. This reaction needed no additional reagent and it was mild, simple, stable and rapid, without any side reaction. By combining the above process with CE separation technique, trimethylamine in royal jelly was completely separated from interfering substances and was successfully detected within 4 min. The limit of detection for acetylcholine was found to be 6.3 x 10(-8) g/mL with a signal-to-noise ratio of 3:1. Acetylcholine in the royal jelly was detected to be 912 +/- 58 mu g/g. The recoveries of acetylcholine chloride in the sample were in the ranges of 92-106%. The coefficients of variation for intra-day and inter-day reproducibility were equal to or less than 4.9 and 6.8%, respectively.