This data set contains raw data supporting the research entitled “Livestock grazing outweighs climate in driving trait variation of a widespread alpine plant” (currently under peer review), which documents how phenotypic traits of a widespread herbaceous plant in the Qinghai-Tibetan Plateau, Herminium monorchis, vary with grazing intensity and environmental conditions. We have uploaded two csv files. The "SiteData" contains fundamental information on the field sites where we conducted field work - 24 natural grasslands in the Qinghai-Tibetan Plateau which span a geographical range of approximately 6 × 7.5° (longitude × latitude) and an altitudinal range of 2600 to 4400 m. The "IndividualData" file contains phenotypic trait information of Herminium monorchis individuals (n = 12 to 16 each site; 326 in total) we collected across these field sites. We hope that these raw data will contribute to future scientific research that aim to unravel determinants of plant trait variations under a changing scenario.