PURPOSE: A monitoring method of petroleum contaminated soils using laser-induced fluorescence technique is provided, thereby reducing the monitoring time and costs because pretreatment of a sample is not required, and easily in-situ monitoring the petroleum contaminated soils by using optical fiber. CONSTITUTION: A device for monitoring the petroleum contaminated soils comprises the parts of: a light source portion(1); a fiber optic probe(2) which transfers laser from the light source portion(1); a sensor(3) which detects fluorescence from the contaminated soils; a fiber optic probe(2') which is connected to the sensor(3) and transfers fluorescence into a light detector; and a detecting portion(4) which detects fluorescence received. The monitoring method of the petroleum contaminated soils comprises using laser-induced fluorescence technique which corrects characteristics of soils using diffuse reflectance, wherein the monitoring method comprises transferring laser from the light source portion(1) to the pet
