Lake sediments preserve different components transported by wind, runoff, and glaciers; therefore, it is important to distinguish the aeolian components in lake sediments. In this study, we used the sediment grain-size characteristics, the end-member modelling algorithm (EMMA), and the thickness of coarse-grained layers in varves to identify aeolian sediments in the KS-2010 core from Kusai Lake. The results indicate that the sand component in the lake sediments can be considered to be related to aeolian processes. Then, we used the sand contents of the surface sediments from 67 lakes to infer the distribution of aeolian activity in China, and the results correlate well with the spatial distribution of the annual maximum wind speed, mean annual blowing sand weather, and mean annual sandstorm. Therefore, the sand component in lake sediments is transported by aeolian processes and can be used as an indicator of wind activity.