Abstract: Water soluble carbohydrates (WSC) are one of the basic metabolic materials in plants and they influence plant growth, development and adaptability to harsh environments. In addition, an increase in WSC content can enhance the use efficiency of protein and dry mass in forage by herbivores, thereby not only enhancing protein production in milk, but also reducing CO₂ emissions from the animal’s rumen. In this paper, we summarize the characteristic of WSC in the plant influenced by the biotic and abiotic factors such as heredity, environment, and cultivation management. WSC contents of plants differed between plant species, organ positions and phonological phases. Environmental factors such as temperature, water, salt and nutrition contents also had major influences on WSC content.