Human activities such as combustion of fossil fuels, intensive agriculture and stockbreeding, have significantly altered the global nitrogen (N) cycle in the last several decades, resulting in increasing the concentrations of nitrogenous compounds in the atmosphere and elevating N deposition to the terrestrial ecosystems. Greater N deposition may change the carbon sequestration on forest ecosystems through affecting the plant growth, litter production, fine root turnover, recalcitrance of N-enriched litter, microbial growth and the DOC dynamic, and has been increasingly concerned worldwide. Based on the available literature, we divided forest carbon pool into aboveground and belowground carbon pool, reviewed the impacts of N deposition on forest carbon sequestration, emphasizing three aspects: (1) Aboveground carbon sequestration. N deposition increase carbon sequestration in "N-limited" temperate forests or have no effects on "N-Saturation" tropical forest, but high N deposition may have negative effects by rising forest mortality. (2) Belowground carbon sequestration. The results of reports are different, ranging from positive to negative depending on forest type, and have few regulation because of its limited researches compared with the researches in aboveground carbon sequestration. (3) The dispute. A range of studies have showed positive carbon increase under N deposition, but the degree of the effects is highly uncertain and may vary by two orders of magnitude. We also reviewed the mechanisms and research methods about the effects of N deposition on forest carbon sequestration in this paper. Finally, the present and future research needs about the effects of N deposition are also discussed.