Abstract: With increasing urbanization, intensive human activities have reshaped the natural geochemical cycles of nitrogen and phosphorus, challenging the efficient utilization and sustainable management of nutrients. The Chengdu-Chongqing Economic Circle was chosen as the study region, which locates at the intersection of the Yangtze River Economic Belt and ‘the Belt and Road’. Based on the net anthropogenic nitrogen (N) and phosphorus (P) input model (NANI and NAPI), the total N and P input of human activities and its composition characteristics were analyzed, the spatiotemporal heterogeneity of N and P input of human activities were clarified, and the relative contribution rates of main socio-economic influencing factors were identified. The results showed that: (1) From 2011 to 2019, the average NANI and NAPI of the Chengdu-Chongqing Economic Circle were 13,063 kg/(km²·a) (in N) and 2,291 kg/(km²·a) (in P), respectively. They are higher than the NANI and NAPI of the Yangtze River Economic Belt and the national average level, but lower than the Yangtze River Delta and the Yangtze River middle reaches city cluster. Non-point sources accounted for a high proportion, with agricultural fertilizer input as the main sources, followed by net food and feed imports. (2) In terms of time scale, from 2011 to 2019, the NANI and NAPI in the Chengdu-Chongqing Economic Circle decreased by 43.2% and 25.9%, respectively. Non-point source NANI and NAPI decreased by 44.9% and 26.8%, while point source NANI and NAPI increased by 7.0% and 3.3%, respectively. In terms of spatial scale, most of the prefecture-level cities with high average intensity of NANI and NAP from 2011 to 2019 were concentrated in the central part of the study region and the neighboring cities of Chengdu and Chongqing. The NANI and NAPI were the highest in Deyang and the lowest in Ya'an. (3) NANI and NAPI were directly correlated with their components. NANI and NAPI were significantly positively correlated with the rural population density and the proportion of cultivated land area, and were significantly negatively correlated with the forest coverage rate (P<0.05). The research shows that the spatiotemporal pattern of NANI and NAPI driven by urbanization is obvious. Relevant management measures in China have a positive effect on it, and regional collaborative governance has become the key to solve environmental problems.