Abstract: The chromatographic fingerprint spectra of tobacco essence were instituted by hyphenation of GC and MS with thermal desorption,and the similarity was calculated by the methods of included angle cosine and Euclidean distance.It was shown that by applying the thermal desorption technique,not only the process of sample pretreatment was shortened and simplified,but also good repeatability of testing was attained,and thus to provide reliable data for the establishment of finger print spectra.Furthermore by using thermal desorption,loss of effective components during pretreatment of samples and pollution of the GC instrument by those high boiling-point substances were also prevented.And by the combination of the 2 easy calculation methods mentioned above,a comprehensive inspection on the quality of tobacco essence was attained.