Abivertinib represents a highly selective irreversible epidermal growth factor receptor tyrosine kinase inhibitor. Two major metabolites of abivertinib, M7 and MII-6, were detected in human plasma, which are recommended to be monitored for safety reasons in clinical trial. A high throughput quantification method utilizing liquid chromatography-tandem mass spectrometry was designed and verified to quantify abivertinib's primary metabolites in human plasma. Solid phase extraction (SPE) was used to process plasma, and then the analytes underwent a gradient elution separation in an Aquity UPLC BEH C18 column (1.7 μm, 2.1×50 mm) with mobile phase A (10mM ammonium acetate comprised of 0.1% formic acid) and mobile phase B (methanol: acetonitrile (2:8, v/v) with 0.1% formic acid). Ion transitions of M7 (m/z 490.2→405.1) and MII-6(m/z 476.2→391.1) were monitored under the mode of multiple reaction monitoring (MRM) and electrospray ionization in positive ion mode. This simultaneous determination method was found to have acceptable precision, accuracy and linearity in 0.5-500 ng/mL range for M7 as well as the 0.5-500 ng/mL range for MII-6, accompanied with a mild matrix effect but high recovery. Further stability assessments indicated that both analytes remained stable throughout the entire experimental process beginning from harvesting whole blood to plasma extracting and analyzing. This article is protected by copyright. All rights reserved.