Traditional Chinese Medicine has been widely used in China and is regarded as the most commonly used treatment. As a natural plant used in traditional Chinese Medicine, Basil has various functions associated with a number of its components. There are many compositions in basil including polysaccharides, naphtha, steroids, flavone, coumarins, vitamins, and so on. Among these, polysaccharides play a significant role in based therapeutics. The article summarizes that basil polysaccharides have a lot of biological activities and pharmacological applications, such as their antitumor activity, antioxidant activity, anti-aging activity, immunity enhancement effect, hypolipidemic and anti-atherosclerotic effects, antibacterial effect, treatment of diabetes mellitus, and so on. This review summarized the extraction method, purification method, compositions, pharmacological applications, molecular weight, biological activities, and prospects of basil polysaccharides, providing a basis for further study of basil and basil polysaccharides.