The existing frozen soil distribution map shows significant differences in classification system, data sources, and mapping methods, reflecting China's phased understanding of the distribution of permafrost over the past half century. In order to more accurately depict the spatial distribution of frozen soil in China and accurately calculate the frozen soil area, this article systematically reviews the existing frozen soil maps, integrates multiple sets of frozen soil mapping results and simulated data of permafrost on the Qinghai Tibet Plateau, unifies the national data time phase, and develops a new version of the national frozen soil distribution map, which objectively reflects the actual distribution pattern of frozen soil in China before and after 2000.

 During the preparation of this data, the following principles were followed for each type of frozen soil:

 1. The base map adopts the Chinese permafrost zoning and type map (1:10 million) (Qiu Guoqing et al., 2000). The distribution of permafrost and permafrost in high mountains outside the Qinghai Tibet Plateau follows the original map; The boundaries between seasonal frozen soil and instantaneous frozen soil, as well as between instantaneous frozen soil and non frozen soil, remain unchanged. The distribution of permafrost in the Qinghai Tibet Plateau region and high latitude permafrost in the Northeast region is updated using the following results.

 2. The distribution of high-altitude permafrost and high-altitude permafrost in the Qinghai Tibet Plateau region was updated using the simulation results of Nan Zhuo Tong et al. (2002). This model utilizes the measured annual average ground temperature data from 76 boreholes along the Qinghai Tibet Highway for regression statistical analysis, obtaining the relationship between annual average ground temperature and latitude and elevation. Based on this relationship, combined with GTOPO30 elevation data (a global 1km digital elevation model developed under the leadership of the Earth Resources Observation and Technology Center of the United States Geological Survey), the annual average ground temperature distribution over the entire Qinghai Tibet Plateau is simulated, and the annual average ground temperature of 0.5C is used as the boundary between permafrost and seasonally frozen soil.

 The distribution of high latitude permafrost in Northeast China was based on the latest results of Jin et al. (2007). Jin et al. (2007) analyzed the annual average precipitation and soil moisture in Northeast China over the past few decades, and concluded that the relationship between the southern boundary of permafrost in Northeast China and the annual average temperature has not undergone substantial changes in the past few decades.

 4. The distribution of alpine permafrost in other regions is updated with the map of glaciers and permafrost deserts in China (1:4 million) (Institute of Environment and Engineering in Cold and Dry Regions, Chinese Academy of Sciences, 2006).

 In terms of classification systems, existing permafrost maps often use continuity criteria for the classification of permafrost, but there are significant differences in the specific definition of continuity. Many studies have shown that continuity standards are a concept closely related to scale and are not suitable for the classification of high-altitude permafrost (Cheng Guodong, 1984; Cheng et al., 1992), and this standard cannot be applied to permafrost distribution models based on grids as basic simulation units. In this article, we abandon the continuity criterion and use the presence of frozen soil within the mapping unit (grid or region) as the standard.

 The new frozen soil map divides frozen soil in China into several categories: (1) high latitude permafrost; (2) High altitude permafrost; (3) Plateau permafrost; (4) High mountain permafrost; (5) Mid to deep seasonal frozen soil: maximum possible seasonal freezing depth>1m; (6) shallow seasonal frozen soil: maximum possible seasonal freezing depth<1m; (7) instantaneous frozen soil: preservation time less than one month; (8) Non frozen soil. Please refer to the documentation and cited references for specific data explanations.