PURPOSE: To obtain an analytical element having at least one layer of reagent layer on a support and developing layer upward and containing glycerol dehydrogenase and oxidation type coenzyme in the developing layer, being excellent in determination property of neutral fat and useful for diagnosis of arteriosclerosis.

CONSTITUTION: The first reagent layer containing gelatin, glycerol dehydrogenase, diaphorase, 3,3'-(4,4'-biphenylene)-bis(2,5-diphenyltetrazolium chloride), 1,2-bis(vinylsulfonyl)ethane, ascorbic acid oxidase, lipoprotein lipase, etc., is provided on a transparent support such as polyethylene terephthalate film and the second reagent layer containing 3-cyclohexylaminopropane sulfone, potassium carbonate, etc., is provided thereon and further a developing layer containing an oxidation type coenzyme such as glycerol dehydrogenase or NAD+ and resin for binder are provided thereon to provide the objective analytical element capable of quickly and simply determining a neutral fat such as blood.