Surfactants is one of the effective methods to promote hydrate formation. The influence of Sodium dodecyl sulfate (SDS) on the formation of hydrate was studied in an autoclave. The microscopic properties for SDS hydrate samples were detected with Raman spectroscopy and powder X-ray diffraction. It was found that the presence of SDS decreased the induction time and enhanced the hydrate growth rate. The microcosmic results showed that the presence of SDS did not change the sI-type hydrate lattice structure and had less impact (a few thousandths) on the crystal spacing compared with ideal sI-type structure and pure methane hydrate. The Raman shift of C-H stretching mode from CH4 encapsulated in large and small cages are all 2904 and 2915 cm-1

which illustrate SDS did not change the large and small cages structure. SDS improved the absolute small cages occupancy (qL) as the absolute large cages occupancy (qS) approached saturation

and this is also demonstrated that SDS can reduce hydration number and increase storage capacity.