Description: This dataset provides hourly electric power load data for all 31 provinces in mainland China. Additionally, it includes comprehensive information about the primary transmission grids that interconnect these provinces, encompassing both High-Voltage Direct Current (HVDC) and High-Voltage Alternating Current (HVAC) transmission lines. Dataset Overview: Electric Power Load Data: The dataset comprises hourly records of electric power consumption for each of the 31 provinces in mainland China. These records span a significant time period, allowing for detailed analysis and insights into electricity demand patterns. Transmission Grid Information: In addition to power load data, this dataset contains detailed information on the primary transmission grids responsible for distributing electricity across provinces. This includes data on both HVDC and HVAC transmission lines, enabling researchers to study the infrastructure that supports the electric power network in mainland China. Potential Uses: Researchers and analysts can leverage this dataset for a wide range of applications relevant with power system operation and expansion. Citation: If you utilize this dataset in your research or analysis, we kindly request that you cite it using the following Zenodo reference: [1] H. Wu and X. Kan, “Hourly electric power load and transmission data at the provincial level in China.” Zenodo, Sep. 06, 2023. doi: 10.5281/zenodo.8322210. Your citation helps acknowledge the effort and resources invested in collecting and curating this valuable dataset.