Infancy acne (IA) can be easy to diagnose yet difficult to evaluate and manage. Evidence-based treatment is inferred from studies in older patients, but it raises relevant safety concerns in children. Quantitative and qualitative modifications in skin surface lipid (SSL) are believed to be among the most critical factors in the pathogenesis of acne [1-2]. But there is no study about IA at molecular levels, which would be an important factor in the pathogenesis. In this study, a powerful analytical technique, ultra-performance liquid chromatography-quadrupole time of flight-mass spectrometry (UPLC-QTOF-MS), and multivariate data analysis were used to investigate SSL variations in non-lesional skin of acne. This article is protected by copyright. All rights reserved.