Rubidium and cesium are critical metal mineral resources. Abundant Rb and Cs resources with low grade (＜10 mg/L) occur in brines from Tibetan salt lakes. According to the supply relationship between hot springs and salt lakes, and their heterogeneity of Li, Rb, Cs concentrations, the possibility of enrichment of Rb, Cs in the lacustrine sediments is evaluated. To verify the hypothesis, 5 brine and sediment samples are collected from the Laguo Co, Nieer Co, Yibu Chaka, Dangqiong Co and Zhabuye Chaka salt lakes, respectively, and sequential extraction experiments are conducted on the sediments. The Rb, Cs concentrations of brines and extracts, and the mineral assemblages of sediments are analyzed. Large heterogeneities exist between the Rb- Cs supply from the rivers and resources in the brines from Laguo Co, Yibu Chaka, Dangqiong Co salt lakes, indicating that abundant Rb- Cs resources occur in the lacustrine sediments. The Rb and Cs concentrations in the sediments are apparently higher than those of the brines; Rb and Cs are enriched in the clay minerals (mainly illite), with the forms of the exchangeable basal position and the irreversible FES and interlayer positions. The potential Rb and Cs resources in lacustrine sediments are much higher than the requirements of large- scale Rb- Cs deposits, and the Rb and Cs concentrations in the clay minerals reach up to several hundreds of ppm. Compared with the development status of Rb resources from the KCl products, and Cs resources from the geyserite, the Rb and Cs resources from lacustrine sediments in the Tibetan salt lakes show great resource potential. This study can be beneficial for the high- efficient utilization of salt lake resources.