甲烷為重要溫室效應氣體之一，大氣中每年約以0.5-0.8 %的速率在增加中，甲烷是極端厭氧之甲烷生成菌於還原環境下分解簡單有機分子所產生，掩埋場是大氣甲烷的重要來源，甲烷的分解主要依賴甲烷氧化菌。本研究選擇台南地區南沙崙掩埋場及城西里掩埋場之不同掩埋齡區進行溫室氣體之量測。南沙崙垃圾掩埋場掩埋齡期約0-2年、3年與5年之平均甲烷釋放量151.9、6.92與6.97 mg m-2h-1，城西垃圾掩埋場掩埋齡期約0-2年、3年與5年之平均甲烷釋放量11.6、51.3與28.2 mg m-2 h-1，顯示南沙崙垃圾掩埋場之溫室氣體釋放量遠高於城西掩埋場，南沙崙垃圾掩埋場掩埋齡0-2年的甲烷釋出率為最高者，而城西掩埋場則以掩埋齡3-5年者高於0-2年。利用分子生物方法建立掩埋場土壤甲烷氧化菌的社會結構，針對甲烷氧化菌的弁鄔夆穧]pmoA與16S rDNA設計專一性的引子，以聚合酶連鎖反應放大DNA，分析不同掩埋齡土壤之甲烷氧化菌社會結構，利用聚合酶連鎖反應進行擴增基因片段，可知在南沙崙掩埋場以Methylocystis sp.菌屬最多。在南沙崙掩埋場以Methylocaldum sp.為主。恆溫孵育試驗中甲烷之削減速率以南沙崙掩埋齡0-2年掩埋場最高，該區域之甲烷氧化菌種類較多，群落結構較為複雜，其甲烷削減率最高。而城西里掩埋場之甲烷削減率較低，且甲烷氧化菌以Methylocaldum sp.為主，推測此菌屬適合在低甲烷濃度環境下生長。 Methane is an important greenhouse gas, and the concentrations of methane increase at the rate of 0.5-0.8 % year-1 recently. Most of methane is produced biologically by a group of strictly anaerobic bacteria in highly reduced environments. Landfill is one of the important biogenic methane sources. Methanotrophs are important regulators of methane fluxes from the landfill to atmosphere. To investigate the methane emission from landfill, gas samples were taken from Nan-Sa-Lun and Cheng-Chi-Li landfills located in Tainan. Average methane emission rate were 151.9, 6.92 and 6.97 mg m-2 h-1 measured in Nan-Sa-Lun landfill by the gas chromatography chamber method in 0-2, 3, and 5 year-old landfill, respectively. Average methane emission rate were 11.6, 51.3 and 28.2 mg m-2 h-1 measured in Cheng-Chi-Li landfill by the gas chromatography chamber method in 0-2, 3, and 5 year-old landfill, respectively. 0-2 year-old landfill had the highest CH4 emission rates in the Nan-Sa-Lun landfill, while 0-2 year-old landfill had the least CH4 emission rates in the Cheng-Chi-Li landfill. To establish the community structure of methanotrophs in landfills , the investigation was revealed by molecular method. The methanotrophic population will be analyzed by the sequence of DNA fragment amplified by PCR using particulate methane monooxygenase A ( pmoA ) gene and 16S rDNA from the total soil population. Methylocystis sp. and Methylocaldum sp. were found to be dominated members of methanotroph community in Nan-Sa-Lun and Cheng-Chi-Li landfills, respectively. The highest oxidation efficiency of methane and the higher methanotrophic diversity were found in the 0-2 year-old Nan-Sa-Lun landfill. Methylocaldum sp. revealed from Cheng-Chi-Li landfill soil could grow in the lower CH4 concentration condition.