Abstract:A new method to detect if synthetic 10-hydroxy-α-decanoic acid was added into pure royal jelly/ lyophilized royal jelly was proposed.This method was conducted by comparing the HPLC/MS/MS spectrum of pure royal jelly/lyophilized royal jelly with those of adulterated samples in order to detect the differences between both sample groups.The maker was found to be presented in royal jelly/lyophilized royal jelly samples adulterated with synthetic 10-hydroxy-α-decanoic acid while could not be detected in any of pure royal jelly/lyophilized royal jelly samples analyzed.In addition，this method is a great innovation in detecting adulterated samples and the pre-processing approch is very simple.This method allowed the detection of synthetic 10-hydroxy-α-decanoic acid in adulterated royal jelly/lyophilized royal jelly samples in concentrations as low as 40 μg/L.