(NOTE: please refer to https://zenodo.org/record/8271847 for an updated version). This dataset includes annual C4 distribution and its uncertainty from 1992 to 2016. We also provide the distribution of C4 natural grasses and C4 crops during the same period. Please refer to manuscript for more details (currently in review): Luo, X., Zhou, H., Satriawan, T.W., Tian, J., Keenan, T.F., Sitch, S. & Smith, N.G. Global C4 distribution estimate constrained by observations and optimality theory. In revision. Correction: we noticed there is an important error in previous version of our C4 map, due to the quality of remote sensing grassland map used. We are now working on providing a new version (V2) in the next few months (Jun 2023).