Lipid emulsion,as an important part of parenteral nutrition support,provides energy and fatty acids.The pro-inflammatory effect of ω-6 polyunsaturated fatty acids has triggered concerns of the possible influence of lipid emulsion on immune function,but few studies prove such adverse immune characteristics.At present new types of lipid emulsion are available by changing the concentration and sources of polyunsaturated acids,mono-unsaturated acid,and saturated fatty acids,attempting to reduce the amount of ω-6 polyunsaturated fatty acids.This paper reviewed the commonly used lipid emulsions at present and related immunoregulation.