|Abstract:Lipid molecules of JPH4, Mildred and McMurray peat core samples from Athabasca region of northern Alberta were systematically analyzed in order to further understand the relationship between peat lipid distribution and its response to the vegetation evolution and climate change. In accordance with the analysis results of n-alkanes, n-alkan-2-ones, steroids, terpenoids and other molecular compounds, combined with chronological data, the paleoclimatic evolution in the study area in the past thousand year has been reconstructed. In the modern Recent Warming (since 1990 cal AD), Sphagnum fuscum widely developed in the Athabasca region under warm and dry climate. In the early Recent Warming, terrestrial plants and S. cuspidata species coexisted in the peatland with periods of dry-humid oscillations observed from 1900 to 1990 cal AD. As Little Ice Age period can be dated in the JPH4 core, the climate became cold and dry after 1560 cal AD when C27-dominated vascular plants accumulated in the JPH4 core. These conclusions are consistent with the information documented in local hydrological and paleoclimate data. Sphagnum fuscum, which favors in dry conditions and has C31 n-alkane dominant distribution, is a special plant type of Sphagnum sect. Acutifolia, , ACL, Paq, C23/（C27+C31）n-alkane proxies are optimally selected to interpret paleoclimate alternations recorded by different types of peat-forming plants. In the representative Mildred peat core, microbial oxidation of related n-alkanes is the primary source of n-alkan-2-one that CPI-ket, ACL-ketand (K23+K25)/(K27+K29+K31) n-alkan-2-one are useful proxies to record paleoclimate variations during peat deposition. The abundance of steroids and terpenoids is significantly higher than that of linear-chain acyclic compounds, proxies of γ-lactone/tocopherols, C29 sterone/C29 sterol, sterol/steroids are preliminarily applied to indicate regional dry-wet and cold-warm changes in the study area, microbial alternation may be the factor affecting these proxies.