Global warming is a serious challenge for human beings. Agroecosystems play an important role in the global warming. Many researches have studied the effects of straw returning on greenhouse gas emissions (GHGs) through field experiments,but the results are very different due to many factors such as experiment sites. To merge these results and study the characteristics of greenhouse gas emissions under different straw returning modes (conventional tillage with straw returning (CTS),no tillage with strawing returning (NTS) and rotary tillage with straw returning (RTS)),the net emission reduction potential of paddy field ecosystem in a certain area can be accurately reflected. Based on 32 documents on greenhouse gas emissions in paddy fields in middle and lower reaches of the Yangtze River, this study collected 173 sets of data and conducted a meta-analysis to study the effects of three straw returning modes on CH_4 and N_2O emissions, and estimated global warming potential and net warming potential in middle and lower reaches of the Yangtze River. The results showed that the effect sizes of CTS, NTS and RTS on annual CH_4 emissions were 0.76, 0.37 and 0.68,respectively. While the effect sizes of CTS, NTS and RTS on annual N_2O emissions were 0.44, 0.36 and 0.52, respectively. In double cropping system,the effect size of annual CH_4 emission from paddy field was RTS > CTS > NTS,while that of annual N_2O emission was RTS > NTS > CTS. In triple cropping system, the effect size of annual CH_4 emission in paddy field was CTS > RTS > NTS,however, that of annual N_2O emission was RTS > NTS > CTS. The effect size of straw returning on annual GHGs in triple cropping system was higher than that in double cropping system. In addition, the types of straw influenced GHGs from paddy fields. The net warming potential was 12 375.55, 11 232.36 and 15 982.87 kg CO_2-equivalent ? hm~(-2) under CTS, NTS and RTS, respectively. Therefore, NTS was the suitable straw returning mode for GHGs mitigation in middle and lower reaches of the Yangtze River.