Abstract: In this paper, Dominican and Mexican blue amber were used for spectroscopic characterization by infrared spectrum and three-dimensional fluorescence spectrum, and then a magnetic nanomaterial polyaniline coated Fe₃O₄(Fe₃O₄@PANI) which can selectively adsorb aromatic hydrocarbon components was prepared and characterized. Determination of fluorescent polycyclic aromatic hydrocarbons in Dominican and Mexican lamella was done by magnetic solid phase extraction-high performance liquid chromatography-fluorescence detector.The results showed that: (1) the infrared spectra of Dominican and Mexican blue amber show strong similarity, which is related to the fact that they belong to the same plant source and have the same resin configuration; (2) In the three-dimensional fluorescence of Dominican and Mexican blue amber, Dominican blue amber has a set of fluorescence peaks around 450, 474 nm and 506 nm, while Mexican blue amber has a set of fluorescence peaks around 441 nm and 465 nm, which is caused by their different aromatic hydrocarbon components; (3) By preparing and characterizing magnetic nanomaterial Fe₃O₄@PANI with selective adsorption of aromatic hydrocarbon components, the organic solution of blue amber was detected by magnetic solid phase extrusion-high performance liquid chromatography-fluorescence detector. The aromatic hydrocarbon constituent perylene with blue fluorescence and the aromatic hydrocarbon constituent benz a anthracene with yellow-green fluorescence were found in Dominican blue amber. And benz a anthracene (yellow-green fluorescence), was found in Mexican blue amber.