Abstract: Disclosed herein are fluorescent markers having a double bond ester group and a method for marking and detecting the same. More particularly, disclosed are a method for identifying oil products, which comprises marking the oil products with fluorescent markers having an unsaturated double bond ester group, adding a developing agent having a function of inducing specific fluorescence to the marked oil products, and detecting the fluorescent marker with a fluorescence spectrophotometer in the UV/VIS region, as well as said markers.