Abstract: The humification degree of peat is a useful proxy index for paleoclimate, although the precise nature of its relationship with paleoclimate remains a topic of debate. This paper presents a comparative analysis of existing studies on humification degree of peat across different regions, with the aim of elucidating the relationship between peat humification degree and paleoclimate, as well as its potential applications in the central Tianshan Mountains, a region of particular interest due to its status as the arid core area of inland Asian. Firstly, in the context of foreign paleoclimate studies, peat humification degree is primarily employed to indicate surface humidity, while in domestic studies, the humification degree is mainly used to indicate the combination of temperature and humidity. Secondly, the key factors influencing peat humification degree are the quantity of plant residues and the microbial decomposition ability, which need to be specifically analyzed in combination with the local geographical environment. Finally, although the relationship between peat humification degree and paleoclimate is still a matter of debate, the recorded paleoclimate information has good consistency, and the response of peat humification degree to the same climate change process varies in different regions. In addition, the experimental study demonstrates that peat in the central Tianshan Mountains is affected by the combination of terrain and hydrothermal conditions. Higher humification degree is associated with the colder climate, while lower humification degree indicate warmer climates, and peat humification degree is found to be intimately linked to the evolution of oasis wetlands.