Abstract: This paper reports GC and GC-MS analyses of the Dibenzothiophene (DBT) -desulfurization pathway of new isolated strain Mycobacterium sp. ZD-19. The experiment showed that the ZD-19 could methoxylate 2-Hydroxybiphenyl(2-HBP) to 2-Methoxybiphenyl(2-MBP) in DBT degradation. It distinguishes that strain ZD-19 have the ability of conversion the hydroxy forms which is the end product via the traditional 4S pathway to methoxy forms. Simultaneously research the effect of the surfactant to the ZD-19 desulphurization activity. The experimental results revealed surfactants could strongly enhance the solubility of DBT in water and improve the mass transfer of DBT between organic and aqueous phases.The experimental results show that the stimulative effect of Soya Lecithin(SL) is most obvious, especially when SL was added at 0.2 g/L in organic and aqueous (o/l) desulfurization reaction system.