Soil organic carbon can be used for climate reconstruction and carbon cycle study. This work assessed the effect of temperature on surface soil δ¹³C by an investigation from 27 sites across a temperature gradient along an isohyet. This study shows that soil type and vegetation type had influences on soil δ¹³C, while temperature was not related to soil δ¹³C. This suggests that organic carbon isotopes in sediments cannot be used for the paleotemperature reconstruction.