We have estimated full-coverage, daily 1-km PM2.5 data from 2000 to 2020 in China using a random forest-based hindcast modeling method which incorporates historical information into modeling. Multiple sources were used as inputs, including MAIAC AOD, meteorological data from CMA, reanalysis data from ERA-5, and other land-related data. The annual average data during 2000-2020 are released here and free for non-commercial use. This manuscript is under review. If you want use our dataset, please cite the following article at this moment. If you want more data (e.g.daily/monthly data) or further collaborate with us, please contact us via qqhe@whut.edu.cn. If you have any question regarding the dataset, feel free to contact me via qqhe@whut.edu.cn. -He, Qingqing, et al. “Satellite-Derived 1-Km Estimates and Long-Term Trends of PM2.5 Concentrations in China from 2000 to 2018.” Environment International, vol. 156, Nov. 2021, p. 106726, doi:10.1016/j.envint.2021.106726. Please note that "0" in TIFF files should be regarded as invalid value!!! If you want to use other datasets, please go to version_3km (10.5281/zenodo.4569557)