It is necessary to evaluate contributions of nature resources on carbon neutralization for tackling the climate change and pursuing the carbon dioxide emission peak. Lakes, which have unique contributes on ecological and humanistic services, were typically considered as carbon source due to swift carbon cycle and large carbon emission. Lakes showed great carbon sink potential with a series of carbon sink characteristics through sorting of latest related researches, comparing carbon sink/source in different types of lake. Intense photosynthesis made lake CO₂ undersaturated, but the raised CO₂ partial pressure pCO₂ and water alkalinity caused by respiration-photosynthesis and carbonate karst erosion also enhanced the lake carbon sink. As more CO₂ were in water and lake carbon cycle, judging lake as carbon source based on pCO₂ over 40 Pa might overlook carbon sink brought by raised alkalinity. The organic carbon accumulation in lake sediment was dominated by balance between respiration and photosynthesis, when heterotrophic microorganisms degraded the deposited tissues and organic matters in time, organic carbon would not accumulate significantly, when respiration was left behind photosynthesis, organic carbon would accumulate quickly. Lake ecosystem productivity determined the capability of carbon fix, constructed a carbon pool which is very important for carbon sink. The carbon fixed in macrophytes were much less than macrophytes, but macrophytes played a role of cornerstone in the progress. In the meanwhile, the latest investigations showed that carbon emission from lake are increasing. The land use issues including deforestation, farmland reclamation, urban development etc. weaken land carbon fix, this external carbon increased carbon emission from lake. Under the pressure of global warming and water eutrophication, the decomposition and mineralization of organic carbon in lake were accelerating, the capability of carbon fix in food chain were descending. To exploit potential carbon sink of lake ecosystem, the results in practice showed that there are three aspects need to be persisted and developed in the future. The first one is restoring macrophytes and improving lake water quality to escort lake carbon sink. Eco-restoration and biodiversity recovery will extend food chain, in which more carbon is transported and stored. The second one is emphasis on sediment carbon accumulation. The specie and source analysis of sediment carbon will provide a convenient way to measure carbon equilibrium instead of full carbon equilibrium analysis, the comparison with land carbon accumulation will highlight the contribution of lake to carbon sink. At last, the technological exploration to collect CH₄ from lake will deal with conflict between the low density in lake and the high density that energy industry demand and open a new filed of carbon neutralization.