Abstract: Lipid emulsions are indispensable components of parenteral nutrition. In clinical practice, it is necessary to understand their physicochemical properties, pharmacological charac-teristics, applicable symptoms, and interactions with other nutrients. Reasonable application of lipid emulsions can provide appropriate energy supply and exert pharmacological effects to improve clinical outcomes of patients. In order to standardize the application of lipid emulsions in parenteral nutrition, Chinese Society of Parenteral and Enteral Nutrition and Clinical Nutrition Committee of Surgical Branch of Chinese Medical Doctor Association organize experts in relevant fields to form this guideline by searching domestic and foreign literature, collecting clinical evidence, and applying the Delphi, in order to promote the rational application of lipid emulsions in parenteral nutrition.