1. College of Earth Sciences, Jilin University, Changchun 130061, China; 

 To complement and verify the Eocene paleoclimate patterns and regularities revealed by other cli? mate proxies in NE China, the cyclicity and details of feldspar/ quartz and monocrystalline quartz/ polycrystalline quartz in the Eocene sedimentary debris of Yilan were analyzed by time?frequency, time?series analysis and noise reduction filtering to reveal their climate change processes. The results show that the Eocene climate in the Yilan region were warm?wet, relatively warm?wet, relatively dry?cold, and dry?cold. During the Eocene, the paleoclimate in the Ypresian stage gradually changed from initial dry?cold to warm?wet, which reached the most warm?wet pattern at the early Lutetian stage, then changed to dry?cold at the late Lutetian stage, and reached the most dry?cold state at the early Bartonian stage, after which the climate fluctuated and warmed up. The results indicated by feldspar/ quartz and monocrystalline quartz/ polycrystalline quartz are in good agreement with the trends inferred from other climate proxies. Feldspar/ quartz and monocrystalline quartz/ polycrystalline quartz have an overall mirror relation? ship, and the higher the mirror degree, the more synchronous the inferred results are, and the inferred results are more reliable. Feldspar/ quartz is sensitive to warm?wet processes on the whole, while monocrystalline quartz/ poly? crystalline quartz is sensitive to dry?cold processes.