Ethanol extractive contents correlate with agarwood quality.To identify characteristics of domestic agarwood for grading,LC-MS combining with chemometrics were used to profile and compare the compositions in ethanol extracts in this study.The main chemicals detected by LC-MS in the agarwood samples were identified as 2-（2-phenylethyl） chromone derivatives with different structures which could be classified in four grades.The results of PLS-DA（Partial least squares-discrimination analysis） based on 8～17 minutes of TIC（total ion chromatograph） showed that the agarwood sample loadings corresponded to relevant grades and that three potential chemicals related with agarwood quality were identified by characteristic fragment ion peaks.It was expected that the results could provide scientific reference for agarwood grading.