Wetland is one of the important ecological zones which is located between aquatic and terrestrial ecosystems, and dissolved organic matter (DOM) is an important loading material for the transfer of nutrients from terrestrial to aquatic systems. The source of DOM in wetland is divided into autochthonous and allochthonous. Source identification of DOM in wetland can benefit to understand the features of biochemical cycles about nutrients in wetland, and then get more information about material circulation between aquatic and terrestrial ecosystem. At present, there are a number of methods to identify the source of DOM in wetland. According to extensiveness and availability of different methods in application, it is mainly introduced the optical method, isotope method, C/N ratio method and biomarker method in the source identification of DOM in wetland in this paper. The results show that optical method, isotopic method and C/N ratio method have been more frequently used in previous researches. In recent years, the biomarker method plays more and more important rule, because the biomarkers such as lignin can not only be used to identify the sources, but also be very sensitive to the changes of different sources. As a conclusion, advantages and disadvantages in present research are summarized, and it is pointed out the research way in the future based on the discussion above.