In the present paper, concentration as an auxiliary parameter was introduced to the synchronous fluorescence to form concentration synchronous fluorescence matrix of the oil spill samples within the concentration range of 10-4-10 g·L-1. Principal component analysis was used to classify the oil spill samples of 0# diesel, 93# gasonline and 5 crude oil simples from the Shengli oilfield. Experiments show that the introducing of concentration can reflect more composition information of the PAHs. This newly method has a better discrimination than the routine method of the synchronous fluorescence spectra obtained from spill oil samples in linear concentration range. It indicates that the spill oil samples of different type and source can be discriminated precisely, even from the same oilfield. The influence of the errors caused in the samples extraction procedure can be eliminated. All the results suggest that the technique may become a more convenient, rapid and accurate means in spill oil identification