The Dali-nor Lake is a typical closed lake in Inner Mongolia, the cold and arid area in Northern China, which has no surface water discharges by rivers. In particular, the surface water of the lake would be frozen with very slowly water flows in winter. The lake can be regarded as nearly sealed and only influenced by groundwater recharges in winter. According to regional hydrologic and meteorological characteristics, the winter is an ideal stage to study the recharge process of bottom water in Dali-nor Lake. Therefore, we collected samples of lake water, lake ice, river water, shallow groundwater and rainfall, and analyzed the values of hydrogen and oxygen isotopes (δD and δ¹⁸O) of these water samples from the lake. The results show that the average values of δD and δ¹⁸O are the heaviest in samples from the lake water and ice, and the average values of δD and δ¹⁸O in shallow groundwater are the lightest, relatively. Meanwhile, the average values of δD and δ¹⁸O are about -31.51‰ and -2.05‰ in bottom water and about -32.77‰ and -2.51‰ in surface water in winter, respectively. But the average values of δD and δ¹⁸O in bottom water are lighter than those in surface water and ice, with values of about -29.12‰ and -1.84‰. In summer, the average values of δD and δ¹⁸O in bottom water are also lighter than those in surface water, with values of about -32.95‰ and 2.13‰ in bottom water and -32.61‰ and -1.99‰ in surface water, respectively. It's likely that the different δD and δ¹⁸O values between bottom and surface water had been influenced by seasonal changes and frozen processes in Dali-nor Lake. As a whole, the values of δD and δ¹⁸O in bottom water are lighter than those in surface water, and the regional differences of δD and δ¹⁸O values are also more distinct than those in summer bottom water. On the other hand, the relationships between water depth and lake water stable isotopes had shown that changes in the water depth were one primary factor that influenced the value changes of δD and δ¹⁸O in bottom water in Dali-nor Lake. As results, the shallow water area, where water depth is lower than 8 m in the northeastern Dali-nor Lake, is influenced visibly by groundwater recharge and again evaporation process. Relatively, the deep water area, which depth is deeper than 8 m in the southwestern Dali-nor Lake, is scarcely influenced by the revalorizations, and the bottom water mass is more stable and longer residence time than that in shallow region.