The KPLANT dataset is a global compilation of whole-plant hydraulic conductance (kplant) measurements, providing harmonised data on plant water transport capacity along the soil-plant-atmosphere continuum. The database contains 3,873 observations from 356 studies, covering 429 species across 245 genera and 100 families, sampled on six continents and seven plant growth forms (tree, shrub, liana, graminoid, forb, stem succulent, fern), spanning 1970 to 2025. kplant values are provided as originally reported and additionally standardised on five normalisation bases (leaf area, sapwood area, wood area, ground area, and whole-plant), together with the underlying water flux and water potential measurements, plant- and stand-level characteristics, and metadata on site, experimental conditions, and source publication. This deposit contains: KPLANT_database.csv - main database with all kplant observations and metadata. Extraction_template.xlsx - standardised template used for data extraction. Extraction_protocol.docx - protocol used by co-authors to carry out data extraction. Individual_datasets.zip - compressed zip file containing the per-study .xlsx datasets. Qc_reports.zip - compressed zip file containing the HTML quality-control reports for individual datasets. Variable definitions, units, and full methodological details are provided in the accompanying data descriptor (Zhao, Mencuccini, et al., Flo. KPLANT: a global database of plant water transport capacity. Scientific Data, in preparation). Code used to build the database and to generate figures and the technical validation analyses is available at https://github.com/vflo/Kplant_database. The automated quality-control procedure used to produce the reports in Qc_reports/ is available at https://github.com/vflo/Kwp_QC.