In order to comprehensively evaluate ecological significance of the watersaving cultivation mode “reserving water in early rice to use for late rice” in double cropping rice of southern China, a field experiment was conducted to explore the combined effects of deep water irrigation in rice translating stage with notillage and rice straw mulching on yield and greenhouse gases emissions. The results showed that, compared with the convention cultivation (CK), the photosynthetic rates of watersaving cultivation mode were increased by 9.6%-15.2% at the heading stage of rice (P<0.01), whereas the water use efficiency of single leaf was decreased by 13.3%-17.4% (P<0.01). Also, the watersaving cultivation model reduced the number of spikelets in single panicle and the setting rate, subsequently decreasing the rice yield significantly (P<0.05). Compared with CK, CH₄ emission in the 20cmwaterlayer irrigation treatment was reduced by 6.1%, but was increased by 6.5% and 4.0% in the 15 and 10cmwaterlayer irrigation treatments, respectively. Meanwhile, the N₂O emissions in the 20 and 15cmwaterlayer irrigation treatments were increased. On the whole, the global warming potential (GWP) and CO₂ equivalent emissions per unit of yield in the 20cmwaterlayer irrigation treatment were lower than that of CK. In conclusion, watersaving cultivation model of 20cmwaterlayer irrigation in the transplanting stage with no-tillage and straw mulching can ensure the success of late rice transplanting, reduce greenhouse gas emissions and improve economic and ecological benefits of rice farming.