Based on the discussion of peat deposition process and the development characteristics of different types of mires, this paper systematically reviewed international paleoclimatic studies about peat sediments from the two perspectives of the common climatic proxies and the carbon records in peatlands. The scopes of application as well as merits and demerits of six common climatic proxies are analyzed in detail,  and the recent hot issues on carbon accumulation and carbon cycles in peatlands are also involved. Finally, the important research fields and contents in peatlands and climate changes are summarized based on four aspects.