As a wide range of chemoautotrophic microbes distributed in the deep sea, Thaumarchaeota performing carbon fixation through oxidizing the low concentration ammonium, make significant contributions to the organic carbon cycling in deep ocean. However, the detailed effects of these deep sea Thaumarchaeota on the dissolved organic carbon in deep have not been well elucidated. In this study, the deep seawater from three stations in the northern South China Sea were collected and conducted cultivation by adding different concentration of NH₄⁺. We found that those cultures with low ammonium can produce nitrite after 28 days. The number of microbe cells also increased accordingly. The analysis of the prokaryotic community compositions showed that the Thaumarchaeota account for 18.5-43.3% of the total communities, indicating that the growth of those deep-sea Thaumarchaeota. At the same time, we found that the growth state of thaumarchaeota has a significant effect on the concentration of DOC in the culture system. In the early stage of growth, the concentration of DOC in the culture system is higher than the control sample, indicating that thaumarchaeota can release a certain amount of dissolved organic carbon into the medium. The released DOC can remarkable promote the growth of a Gammaproteobacteria, Ralstonia. When thaumarchaeota reached the late stage, the DOC concentration (36 μM) of the system was significantly lower than that of the control sample (59 μM), indicating that the released DOC by thaumarchaeota might stimulate the degradation of original DOC from deep sea, which called priming effects. Through bottle experiments, we found those DOC released by thaumarchaeota might have priming effects on the original DOC from deep sea, which shed light on revealing the importance of thaumarchaeota in the organic carbon cycling in deep ocean.