A stalagmite(SZ2) collected from Suozi Cave in NE Sichuan, China, established with δ13C data, provides a high resolution spleothem δ13C time series during 120~103ka. The SZ2 δ13C record appeared to be significantly different from the long term change trend of the δ18O record. The δ13C record and growth rate of SZ2 show the consistency in the whole trend, which mainly reflected that CO2 degassing and carbonate sediment influenced by drip rates over a speleothem surface influence the SZ2 δ13C record on the long time scale. On a short time scale, the SZ2 δ13C record appeared to be consistent with the change trend of the δ18O record. The SZ2 δ13C record may be mainly influenced by vegetation above the cave(proportion of C3 to C4 plant), density of vegetation, soil microbial activity and cave ventilation.