Disclosed is a method for selectively eliminating triglycerides in lipoproteins other than low density lipoprotein, which method allows one to provide a method for directly and differentially quantifying LDL-TG in a sample with excellent simplicity, specificity and accuracy using an automated analyzer or the like without performing a laborious operation of pretreatment such as centrifugation or electrophoresis. The method for eliminating triglycerides in lipoproteins other than low density lipoproteins includes allowing lipoprotein lipase, cholesterol esterase, glycerol kinase and glycerol-3-phosphate oxidase to act on a sample in the presence of a surfactant that acts on lipoproteins other than low density lipoprotein and/or a surfactant having LDL-protecting action, and eliminating hydrogen peroxide produced thereby.