Normal adult adipose tissue is composed of adipocytes and pericellular matrix components including collagen fibers, blood vessels, fibroblasts and immune cells. Adipose tissue is composed of 50% of adipocytes and 96% of the volume, so the subcutaneous fat we usually see in animals is mainly yellow adipocytes rich in lipid droplets. As the main structural unit of adipose tissue, the main function of adipocytes is to store and mobilize lipids. The general number of adults is (25~4.5)×1000, while the number of obese people can reach 9×1000. Its size depends on the amount of lipids it contains, with a diameter of 20-200 μm and a volume that can vary by hundreds of times. So exactly, fat fat is mainly fat cells obesity. The remaining 50% of adipose tissue is composed of blood vessels, nerve and connective cells, and macrophages, etc. These cells are numerous but small in size, accounting for only 4% of the volume. However, they are important for the physiological activities of adipocytes such as nutrition, migration, and conversion to apoptosis. What we clinically aspirate out or perform transfer is mainly adipocytes, i.e., yellow granular adipose tissue that can be seen with the naked eye. The fat cells must be protected from breakage and destruction during the procedure in order to maximize the survival rate of the graft.