In order to reveal the effects of straw and biochar amendment on greenhouse gases(GHG)emission and crop yield,the farmland ecosystem of maize-wheat rotation in Guanzhong Plain of China was taken as the study area.The annual GHG emissions(CO_2,CH_4,and N_2O)from a wheat-maize rotation system with straw and biochar amendment were monitored using the static opaque chamber and gas chromatography technique.Five field treatments in the study including conventional fertilization (N),fertilization and 4 t/hm~2 straw (NS)amendment,fertilization and 4 t/hm~2 biochar(NBC_(low))amendment,fertilization and 8 t/hm~2 biochar(NBC_(high))amendment.CK was without straw,biochar and fertilizer.The results showed that:(1)compared with N treatment,annual N_2O emission decreased by 13.21%and 23.75%under NBC_(low) and NBC_(high)treatment,respectively,and no significant difference was observed under straw application;(2)compared with N treatment,annual CO_2 emission increased by 44.06%under NS treatment,but decreased by 9.94% under NBC_(high)treatment;(3)compared with N treatment,annual CH4 emission increased by 42.32%, 76.38%and 73.23%,respectively,under NS,NBC_(low)and NBC_(high)treatment;(4)yield increased by 13.73%,20.37% and 7.56%,respectively,under NS,NBC_(low)and NBC_(high)treatment as compared to N treatment,and decreased by 10.64% under NBC_(high)treatment as compared to NBC_(low)treatment;(5)the NGWP decreased by 33.59 t/hm~2 and 48.33 t/hm~2,respectively,under NBC_(low)and NBC_(high)treatment as compared to N treatment,and the NGHGI decreased by 2.53 t/t and 4.21 t/t,respectively,under NBC_(low) and NBC_(high)treatment as compared to N treatment.In summary,it is concluded that biochar application of 4 t/hm~2 can be used as an effective management to carbon sequestration and increase crop yields under the wheat-maize rotation system in Guanzhong Area.