Both the microbes and the dissolved organic matter are large complex entities in the ocean. Knowledges were gain with the development of stat-to-art techniques that thousands of microbial species and DOM molecules were discovered and identified in various oceanic environments. Both the microbes and DOM are diverse in their own properties as well as their intricate relationships. Systematical thinking was brought into the study to provide another point of view to scan the complex interactions between microbes and DOM. Links were built between individual microbial species and DOM molecules based on their varying connections, thus complex networks were formed showing overall results of individual interactions. Key species would be predominated in the degradation process of labile DOM components and a major proportion of the marine DOM would be invariant and co-occurrent with the dominant key species on the contrary. The fate of DOM was specifically targeted to certain microbial species, and the patterns of microbial community were influenced by the DOM compositions. Applications of the statistical tools took a step further to get a glimpse at the complexity of microbial-DOM interactions in the gaining big datasets, from individuals to the whole.