Abstract: The reconstruction of river paleodischarge can determine the quantitative hydrologic and climatic characteristics of the drainage basin. Three paleochannel cross-sections of the Yangtze River at Nanjing section are restored by borehole data. Based on ¹⁴C and ESR (Electron Spin Resonance) ages and analysis of sedimentary facies, the paleochannel between the -50--90 m existed in the last glacial maximum (LGM). According to the sediment sizes, the right sediment incipient formulae calculate the average vertical velocity at different depths. Then, the average vertical velocity multiplies by the corresponding area to get the unit paloedischarge. Finally, adding all of the unit paleodischarge reconstructs the paleodischarge in the LGM. The paloedischarge in the LGM is about 10 000-12 000 m³/s that is equal to the present January average annual discharge. Longitudinal gradient in the LGM is about 4×10^-4-5×10^-4 and is the same with the present upper Yangtze River at Pingshan-Yibin section.