Abstract: A quantitative source apportionment method based on nontarget high-resolution mass spectrometry (HRMS) data of pollution sources and pollution receptors includes: acquiring samples of pollution sources and receptors, pre-processing samples to extract trace organic pollutants; acquiring chromatography-HRMS nontarget data; pre-processing raw data to obtain a HRMS dataset including a mass-to-charge ratio, a retention time, and a peak area; determining a source-sink relationship based on positions of pollution sources and receptors; constructing an input matrix by combining the HRMS dataset and using each sink as a group; adopting an expectation-maximization method or a Bayesian method to calculate contribution of each source based on a standardized input matrix. Beneficial effects at least include the follows.