The seagrass bed is one of the most productive wetland ecosystems, providing valuable ecological goods and services. About 2%-5% of seagarss populations disappeared each year on Earth, which has been due to a wide variety of human and natural disturbances in recent years. The dynamics of non鄄structural carbohydrates (NSC) reserves play an important role in determining seagrass growth and its response to environmental disturbances. In order to improve our understanding of the NSC in seagrasses, the information on the NSC responses to environmental stresses, such as light, nutrient, salinity, ocean acidification, temperature, sulfide and animal grazing were summarized. Seagrasses are particularly sensitive to reductions in light availability, where small decreases can cause significant declines in growth and distribution. During periods of reduced photosynthesis caused by light limitation, the stored NSC in belowground tissue can be reallocated to meet the C (Carbon) demand of seagrasses. Thus, seagrass species with higher belowground biomass and carbohydrate storage capacity can tolerate longer period of light limitation. Nitrogen assimilation requires carbon skeletons for the respiratory pathway and reserves. Under excessive nitrogen conditions, carbon requirements for synthesizing amino acids may exceed carbon fixation capacity, leading to a decrease in NSC concentration and NSC reserves reallocation. Under