Abstract: Regional total water pollutant allocation is the key to inter-regional equitable coordination and efficient economic development. In order to balance efficiency and equity, the optimal efficiency solution with the smallest distance from the ideal equity solution s taken as the final solution, thus the total emissions allocation model s constructed and the total COD allocation scheme s calculated for each prefecture-level city for the "14th Five-Year Plan". Results show that: (1) Yancheng and Xuzhou, which halarger historical COD emissions, allocated 14.2% and 12.1% of Jiangsu Province's emissions, which manifest historical and developmental equity, and they b18.5% and 10.8% of the province's emissions reduction quota, evidencing the principle of equity of "whoever pollutes governs"; (2) Wuxi and Changzhou, higher economical level and unit emission output, in line with the requirement of efficiency prioritization, as the final scheme of emission allocation s larger than the equity scheme. Based on this, Jiangsu Province prefecture-level cities divided into four categories based on COD emission reduction rate and per capita GDP, so as to separately explore and discuss the path of sustainable development.