Carbon isotope fractionation is sensitive to the environment factors associated with plant growth; thus, it can be used as a proxy to reconstruct past climate and environmental conditions. We investigated the relationship between carbon isotope signatures (delta C-13) and its fractionation (Delta delta C-13) of Tamarix leaves and a set of climate and environmental factors in the Southern Margin of the Taklimakan Desert (SMTD). A principal component analysis was used to condense these factors as the temperature-, wind-, precipitation-, and humidity-related index, explaining 51.0%, 18.0%, 5.1%, and 4.7% of the total variance, respectively. Combined with the correlation results, temperature is identified as the key growth-limiting factor for Tamarix in the SMTD. Specifically, 6 13 C has a statistically significant correlation with the lowest temperature in June (LTJun)(r = 0.717, p = 0.000), and Delta delta C-13 has a statistically significant correlation with the annual mean of the highest temperature (AMHT) = 0.700, p = 0.000). Based on these high correlations, we reconstructed the LTJun AMHT records in the past 400 years using delta C-13 and Delta delta C-13 of Tamarix leaves deposited in the Tamarix cone. These records revealed a long-term fluctuation in temperature that can be divided into four sub-periods, including the history cold period (1600-1685), history warm period (1686 - 1913), modern cold period (1914-1993), and modern warm period (1994-2010). These records provide useful insight into the paleoclimate and environmental change in this arid region.