A thermophilic naphthalene-and aliphatic hydrocarbon-degrading bacterium SH-1 was isolated from a deep oil well and identified as a Geobacillus sp.based on 16S rDNA sequence analysis and the morphological,biochemical and physiological characteristics of the bacterium.Strain SH-1 grows at temperatures between 45 and 80 ℃ and at pH values between 6.0 and 8.0.N-alkanes from C12 to C33 in crude oil and naphthalene were effectively degraded by strain SH-1,and this strain could readily utilize these compounds as its sole carbon and energy resources.During the degradation of naphthalene,five metabolites,namely,1-naphthol,1,2-dihydroxynaphthalene,trans-o-hydroxybenzylidenepyruvate,2E)-3-(2-hydro xyphenyl)prop-2-enal,and benzoic acid were successfully detected and identified based on GC-MS analysis.Strain SH-1 initiated its attack on naphthalene by a monoox ygenation at its C-1 to give 1-naphthol and further monooxygenation at C-2 to produce 1,2-dihydroxynaphthalene.