This is the README file for Chen X, Shi Q, Zhou X, Liu X (2019) Data from: Molecular characterization of aldehydes and ketones in particle phase of mainstream and sidestream cigarette smoke. Dryad Digital Repository. https://doi.org/10.5061/dryad.6v1r5n8 The associated article is published in Royal Society Open Science at https://doi.org/10.1098/rsos.181832 Please cite the original article when using these data. This data package contains 2 .zip files data.zip data_Excel.zip 1. The Positive ion ESI FT-ICR MS of the AKPs after GirT derivatization (Figure 2a in the article): The original FT-ICR MS data can be opened by “Bruker Daltonics DataAnalysis”. We have converted the data to another format that can be opened by “Agilent ChemStation”. In addition, we have extracted the MS information from the original data and placed it in Excel documents. The data in Excel format is available in the file data_Excel.zip 2. The Positive ion ESI Orbitrap MS of the aldehydes and ketones in particle phase of mainstream and sidestream smoke (Figure 5a in the article): The original Orbitrap MS data can be opened by “Thermo Xcalibur Qual Browser”. We have also extracted the MS information from the original data and placed it in Excel documents. The data in Excel format is available in the file data_Excel.zip 3. The GCMS of the aldehydes and ketones in particle phase of mainstream and sidestream smoke (Figure 4 in the article): The original Orbitrap MS data can be opened by “Thermo Xcalibur Qual Browser” and cannot be converted to open source formats. Because each peak in the gas chromatogram corresponds to the specific mass spectra of the compound, we cannot extract the MS information from the original GCMS data.