Peatsoil istechnically a soilwhich containsappreciablequantities of organic matter that is considered to dominate the soil properties. It has been estimated that the total area under peat land is around 240 million ha worldover, includingabout 14.9 million ha occurred in Indonesiaand 300,000 ha occurred in Japan.Peat soils in Indonesia and Japan havefor long time been used for paddycultivation. Some portions of peat soils in Indonesia are also use for estate crop cultivation likecoconut, pine apple, and presently oil palm.The utilization of peat soil for estate cropscultivation iscommonly started by constructing drainage ditched to release the excessive water. Over drain,coupled with human carelessness,may lead the peat soil to front of forestfire. Intermittent drainage is practiced in paddy filed to remove hazardous substance from paddy filed. Peat soil has attracted considerable attentionsglobally due to its potent as source of greenhouse gases (GHGs) and subsequent global warming. This paper is aimed at summarizingthe response of microbes to drainage and forestfireof peat soils. The informationwasmainly gainedfrom the studies carried out by author in Indonesia and Japan, using plate count, adenosine tri phosphate (ATP)measurement, and denaturized gradient gel electrophoresis (DGGE)methods. The results indicate that forest fire and intermittent drainage (draining peat for less than 6 days) did not affect the population and community structure of GHG related-microbes.However, the intermittent drainage and forest fire reduced the activities of methanogens and methanotrophs, respectively. Moreover, long term drainage affects the population of nitrifiers and denitrifiers. Water filled pore space (WFPS) seemed to be themost influential soil properties to GHGs related-microbes in responding drainage and forestfire.