Laboratory experiments were conducted to examine the effect of straw biochar addition on acidified tea garden soil amelioration and greenhouse gas emissions, different amounts of wheat-straw derived biochar (Control: 0 g·kg~(-1); Low biochar: 8 g·kg~(-1); Medium biochar: 24 g·kg~(-1); High biochar: 48 g·kg~(-1)) were added to tea garden soil. The results indicated that the adding of biochar significantly reduced acidified tea garden soil N_2O emissions compared with CK (no wheat-straw derived biochar).But the effect did not increase with increasing application rate of the straw biochar, with the 24 g·kg~(-1) rate had the largest prominent effect. The cumulative N_2O fluxes were 2.366, 0.444, 0.142 and 0.207 mg·kg~(-1) for CK, B1,B2 and B3, respectively. Compared with CK treatment, the global warming potential of low biochar and medium biochar treatments decreased by 33.45% and 25.77%, respectively, while there was no significant difference between the high biochar treatment and control treatment. The result indicated that the low and medium biochar applied was more beneficial to carbon sequestration and reduce greenhouse gases emission in tea garden soil than the high biochar applied. Additionally, the biochar could significantly increase the pH value in acidified tea garden soil, indicating that the higher biochar addition with the higher soil pH value. Therefore, the straw biochar addition had better effect on acidic soil amelioration. The result showed that soil N_2O flux was significantly correlated with soil pH, indicating that the increasing of soil pH may be an important factor to decrease N_2O emission.