Abstract: New productivity forces (NPF) are crucial for advancing high-quality economic growth and achieving modernization in the Chinese context. This paper utilized Theil index, exploratory spatial-temporal data analysis framework, and spatial econometric model to assess and examine the spatial-temporal evolution pattern and influencing factors of NPF development in the Yangtze River Economic Belt (YREB) through a comprehensive evaluation index system. The results showed that: (1) The NPF advancement in the YREB increased from 2013 to 2021, however it remained relatively low. The average level of NPF in 2013 was 0.040, while in 2021 it rose to 0.101. The spatial distribution exhibited a pattern of high in the east and low in the west, high in the north and low in the south, indicating a clear regional clustering. The cities with high value points included Shanghai, Suzhou, Nanjing, Hangzhou, Chengdu, and other municipalities that are directly under the Central Governmentthat or are capital cities. The cities with low value points included Guang'an, Bazhong, Zhaotong, Dazhou, Suining, and other upstream cities. (2) There were notable disparities in the NPF progress across the entire region, with variations observed in the upper, middle, and downstream areas. These differences initially decreased and then increased. Within the regions, the disparities ranged from strong to weak in the upstream, downstream, and middle reaches, respectively. The contribution rates ranging from large to small to the overall regional development differences followed the order of downstream, middle reaches, and upper reaches. (3) The global spatial autocorrelation of NPF development was evident, with a correlation degree that fluctuated between weakening and strengthening. Both overall and local spatial structures remained relatively stable, displaying a strong spatial dependence during the evolution process, and indicating a dynamic spatial integration dominated by high cooperative elevation. (4) In terms of direct effects, the improvement of government administrative capacity had negative effects on the urban NPF development, while other factors had positive effects. In terms of spatial spillover effects, economic development and the improvement of marketization degree had positive spatial spillover effects on the NPF, while other factors had negative effects. (5) Thus, in urban construction, it is essential to establish policies and strategies to enhance the NPF growth based on local circumstances. Secondly, it is crucial to leverage regional economic development, financial restructuring, industrial upgrading, system enhancement, market reform, and government function transformation to support the NPF advancement. Lastly, it is necessary to strengthen the regional coordination mechanism, boost the impact of central cities on promoting small and medium-sized cities, and foster collaboration across many sectors to support the growth of the NPF.