Methane，an important trace gas in the atmosphere,plays major roles in global warming and atmospheric chemistry. The world's Ocean is both a source and a sink of atmospheric methane .The studies of dissolved methane in the ocean are helpful to understand the contribution of the ocean to atmospheric methane and global warming. This paper described the advances in the studies of dissolved methane in the seawater, especially its distribution in the ocean, the estimation of its airsea flux and its biogeochemical cycles in the ocean. It also discussed the disadvantages in the present study.