A greenhouse pot experiment was carried out in rice-growing season to investigate the effects of water management on methane (CH₄) emissions. Four treatments including continuous flooding (CF), keepinng 3 to 5 cm water layer during the rice-growing season; early aeration (EA), 24 days after rice transplanting; normal aeration (NA), 30 days after rice transplanting; late aeration (LA), 38 days after rice transplanting were dedicated to this experiment. The results showed that CH₄ emissions of different aeration treatments sharply increased after the beginning of mid-season aeration and then quickly decreased to near zero. Significant negative correlations between CH₄ emission and soil Eh were discovered during rice-growing period (p<0.01). The total CH₄ emission of different aeration treatments during aeration periods accounted for 38.75%~52.21% of those emitted during the whole rice-growing season. The average CH₄ fluxes of EA, NA and LA were 0.86、0.96、1.45 mg/(m²·h), respectively. So it is easily found that the later it began to aerate, the more CH₄ emitted. The CH₄ emission of treatment CF was 12 ~ 20 times more than those of aeration treatments. Significant positive correlation between CH₄ flux and soil temperature of treatment CF was found during rice-growing period excluding the first 30 days (r=0.682^**, p<0.01).