Improvement of soil organic carbon is key to the sustainable development of vegetables in China.There is large difference in the increase of soil organic carbon among different organic fertilizers.Taking the Chinese cabbage in southwest China as the research object，the study was carried out to compare the effects of different organic fertilizers on crop yield，soil organic carbon content and nitrogen and phosphorus balance for new open-field vegetable system in Southwest China during 2019～2020，furtherly identify the suitable types of organic fertilizer in this region.The field experiment was conducted with six treatments:no fertilizer (CK)，conventional practice (CONV)，biochar (BC)，chicken manure compost (CM)，kitchen waste compost (KW) and maize straw (ST).Each treatment was repeated for three times.CK treatment didn’t apply fertilizer，and the input of soil carbon，nitrogen，phosphorus fertilizer in of CONV treatment was C 1200 kg/hm²，N 450 kg/hm²，P2O5 450 kg/hm²，respectively.The input of soil carbon，nitrogen，phosphorus fertilizer in other four organic fertilizer treatments was C 1700 kg/hm²，N 250 kg/hm²，P2O5 160 kg/hm²，respectively.Our results indicated that compared with CONV treatment，when the rate of nitrogen and phosphorus fertilizer in BC，KW and ST treatments were reduced by 44.4% and 64.4%，respectively，the yield maintained the same level.Meanwhile the soil organic carbon of optimized treatments was significantly increased by 55.2%～78.3% and 14.3%～31.2% compared with that of CK and CONV treatments，respectively.The content of soil organic carbon in BC and KW treatments was the highest among those four optimized treatments.The organic carbon content of BC treatment was 10.1% and 14.9% higher than that of ST and CM treatments，and the corresponding value in KW treatment was 2.75% and 7.18% higher than that of ST and CM treatments，respectively.There was no significant difference in soil nitrogen and phosphorus content among different organic fertilizer treatments.The use efficiencies of nitrogen and phosphorus fertilizer in optimized organic fertilizer treatment were higher by 7.6%～16.3% and 7.72%～9.52% than those of CONV treatment，respectively；the highest use efficiency of nitrogen and phosphorus fertilizer was observed in BC treatment，and followed by KW treatment.In conclusion，BC and KW treatment performed best based on comprehensively considering the soil organic carbon increase，yield，soil nutrient content and fertilizer use efficiencies，compared to other treatments.At the same time，these results show that the addition of biochar and kitchen waste recycling organic fertilizer under the optimized fertilizer management conditions is an important measure to ensure the soil health and sustainable production for open-field vegetable system in Southwest China.