An incubation experiment was conducted to investigate the effects of biochar and biological nitrification inhibitors on N2O and CO₂ emissions from intensive cultivated greenhouse vegetable soil in the Loess Plateau. The effects were also compared with the widely used synthetic nitrification inhibitors. This experiment included six treatments as following:no fertilizer(CK)，nitrogen fertilization(N)，nitrogen fertilization+biochar(N+BC)，nitrogen fertilization+dicyandiamide(N+DCD)，nitrogen fertilization+neem seed oil(N+NEEM)and nitrogen fertilization+methyl 3-(4-hydroxy.phenyl)propionate(N+MHPP). The results showed that nitrogen fertilization strongly increased soil mineral nitrogen content and N2O and CO₂ cumulative emissions. The greatest soil mineral nitrogen content and N2O and CO₂ cumulative emissions were observed in the N treatment. Among all tested inhibitors，only DCD addition significantly reduced NO^3--N content but increased NH4+-N content. Compared with N treatment，the N+BC，N+DCD，N+NEEM and N+MHPP treatments significantly reduced the cumulative N2O emissions with 21.9%，71.4%，19.5% and 37.9%，respectively，and CO₂ cumulative emissions with 12.0%，35.7%，15.8% and 10.4%，respectively. In summary，biochar and biological nitrification inhibitor are effective in inhibiting N2O and CO₂ emissions from greenhouse vegetable soil in Loess Plateau. However，the effects of greenhouse gas emission reduction were not superior to the widely used synthetic nitrification inhibitor(DCD)at the current dosage.