The root system is an important organ of the tree and plays two main roles, one of which is to support the tree, which is mainly performed by the coarse roots, and the other is to absorb water and nutrients, which is mainly performed by the fine roots. Fine roots are not only responsible for water and nutrient uptake, but also contribute significantly to carbon sequestration and net primary productivity (NPP) in forest ecosystems. Fine roots are an important component of the root system, an important soil resource in terrestrial ecosystems, and a mediator of soil geochemical cycling, and are the most active component of the root system. Fine root production (FRP) is the largest component of below-ground production and plays a critical role in the allocation and cycling of carbon and nutrients in forest ecosystems. Root order has a large effect on the FRP. At present, there is fewer large-scale research on FRP based on the method of segment order-based classification with the natural secondary forests of 16 sites in China as a whole. In this study, we conducted a 1-year experimental study of fine root production at the stand level in natural secondary forests at 16 sites in China using the segment order-based classification method to explore the distribution patterns of fine root production in natural secondary forests at 16 sites in China. The results showed that the distribution pattern of fine root production increased gradually from north to south. Absorptive fine root (AFR) production, transport fine root (TFR) production and FRP were the highest in Jianfengling, Hainan, with (115.42±17.87) g/m², (298.6±76.82) g/m² and (414.01±84.05) g/m², respectively, and the lowest in Huzhong District, Daxing'anling, with (11.25±1.28) g/m², (12.44±0.97) g/m² and (23.7±1.21) g/m², respectively. Taiyue Mountain, Shanxi, Yao Luoping, Anhui, and Huitong, Hunan were significantly lower than those in neighboring latitudes (P < 0.05). FRP was (50.89±5.58) g/m², (58.85±17.24) g/m² and (67.26±15.31) g/m², respectively. Mean annual temperature (MAT) and mean annual precipitation (MAP) were significantly and positively correlated with AFR production, TFR production and FRP, while latitude was significantly and negatively correlated with AFR production, TFR production and FRP. China's forest ecosystems are huge and diverse, accounting for a large proportion of the global forest ecosystems and playing a very important role in carbon and nutrient cycling at the global scale, whereas global databases seldom cite data from China's forest ecosystems. Therefore, it is of great importance to carry out a study on fine root production on a large scale based on the segment order-based classification method in natural secondary forests at 16 sites in China.