Abstract: OBJECTIVE To investigate the influence of difference reference substances on the determination of residual solvent xylene. METHODS Using references substances of ethylbenzene, p-xylene, m-xylene, o-xylene (four components of xylene) to determine xylene from five samples. RESULTS The ratio of ethylbenzene, p-xylene, m-xylene and o-xylene in the five samples were variable, the contents of xylene calculated from the four references were different. CONCLUSION The determination of residual solvent of xylene may exist deviation using xylene as the reference substance.