In 2005, diurnal variations of CH₄ fluxes from rice-vegetated and non-rice-vegetated fields at tillering stage and under clear weather condition was monitored using a closed chamber technique. The results showed that the variation pattern of CH₄ emitted from all the fields followed a single-peak mode with the peak appearing at 14 o'clock in the afternoon. Significant positive correlations were found between CH₄ flux and soil temperature at 5 cm (p<0.05). The diurnal mean CH₄ flux from rice-vegetated field was significantly higher than that from non-rice-vegetated field(p<0.05). About 8~10 o'clock was recommended as the optimum sampling time for rice-vegetated plot, while about 18 o'clock was recommended as the optimum sampling time for non-rice-vegetated plot.