Abstract: 【Objective】 To explore the response of annual carbon at different levels to tillage measures, so as to provide reference for rational tillage measures for carbon sequestration in soybean soils under multiple sowing conditions. 【Method】 Under field drip irrigation in 2017, four soil tillage treatments were set up, namely, tillage mulching (TP), tillage (T), subsoiling (ST) and no-tillage (NT). The effects of different tillage treatments on the contents of soil organic carbon (SOC), microbial organic carbon (MBC) and particulate organic carbon (POC) in different soil layers were studied. 【Result】The results showed that compared with T and TP treatments, NT and ST treatments were beneficial to increase the mass fractions of SOC, MBC and POC in 0-10 cm topsoil, and there was no significant difference. In the 10-30 cm tillage layer, TP treatment could better maintain the mass fractions of SOC, MBC and POC in soil than the other three treatments. However, fewer than 30 cm of soil depth, the differences of MBC and POC mass fractions between ST treatment and the other three treatments gradually increased and showed significant differences. At the depth of 0-60 cm, the proportion of microbial organic carbon and particulate organic carbon in total organic carbon ranged from 1.29% to 2.35% and 17.81% to 31.99%, respectively. The proportion of microbial organic carbon and particulate organic carbon in total organic carbon reached the highest point at the depth of 60 cm, and the ratio of microbial organic carbon to total organic carbon was ST > TP > T > NT.【Conclusion】In summary, both subsoiling and no-tillage can effectively increase the mass fraction of SOC, MBC and POC in the topsoil, and the mass fraction and ratio of MBC and POC of subsoiling were significantly improved at the depth of 30 cm. The soil layer 20-30 cm tillage mulching can better maintain the mass fraction of SOC, MBC and POC in the soil.