Allelochemicals are secondary metabolites or transformants released from plants into the environment and can influence the nearby plants harmfully or beneficially. In this study, the allelochemicals in typical yellow brown soils with different years of tobacco continuous cropping were detected by GC-MS after being extracted by methanol and ethyl acetate respectively. The results showed that in total 13 kinds of allelochemicals were detected, including 5 kinds of the acids, 3 kinds of the esters, 2 kinds of the phenolics, 2 kinds of the aldehydes and 1 kind of the alcohols, among of which, phthalic acid, p-hydroxybenzaldehyde and di (2-ethylhexyl) phthalate were first reported in tobacco study. The contents of allelochemicals in rhizosphere soil showed an increasing trend with the year of tobacco continuous cropping. Comparing with 1 a of tobacco planting, the contents of phthalic acid, benzoic acid, terephthalic acid, diisobutyl phthalate, 3,4-di-tert-butyl-pheno and 2-Methoxy-4-formylphenol increased more than 10 times under 10 a continuous cropping, which could possibly reduce or deteriorate the yield and quality of tobacco.