Lake sediments record large amount of environmental information from the watershed over a long time, and has become a high-resolution archives for investigating the lake environmental change at the centennial scale. In this paper, we analyzed the features of radionuclide profiles through the combined dating method of ²¹⁰Pb_ex and ¹³⁷Cs, investigated the temporal and spatial changes of sedimentation rate, and extracted the environmental information indicated by sediment particle size to reveal the patterns of the sedimentary environment during the last century. The results showed that ²¹⁰Pb_ex profiles presented four stages:a multi-stage decay, a mixed-decay-equilibrium, a decay-background and a no-deposition. The sediment depths of 200 cm in the three major lake bodies covered a chronological span of 127-162 years, and a depth-age relationship was constructed for Lake Dongting sediments. The mean mass accumulative rate (MAR) ranged from 1.47 to 3.11 g/(cm²·a), demonstrating an overall spatial characteristic of the highest MARs in the south, and higher in the west than the east. Since 1900, MARs in Lake Dongting increased 3-7 times, showing an upward trend in the chronology. The depositional change of sediment grain size in Lake Dongting was characterized by three stages and two transitional periods, which corresponded well with anthropogenic activities such as deforestation, hydrological construction, and afforestation in the basin in the period. These findings suggested that anthropogenic activities had been an important factor for sediment deposition in Lake Dongting. The foundings in our study can provide a theoretical reference for enhancing the ecological protection of the lake and its watershed.