Abstract:The effects of two organic fertilizers and five chemical fertilizers on the amount of methane producing bacteria (MPB) and amount of methane release under the condition of pot culture were studied. With improved hungate anaerobic technique. the amount of hydrolytic fermentative bacteria(HFB), hydrogen-producing acetogenic bacteria(HPAB), Methanogenic bacteria (MB) in the submerged paddy soil planting rice crop were determined by the MPN(the most prbbable number)method.The amount of methane released were collected in situ field method, and the amount of methane were determined at once with chromatography. The results obtained showed that the application of organic fertilizers accelerated the amount of MPB and methane released. The effects of green manure were the most significant. Ammonium dicarbonate, ammonium sulfate, urea and ammonium chloride could slightly accelerate the amount of MPB and methane released while sodium nitrate inhibited them.