This study was conducted to investigate the biochemical properties of isolated bacteria, low temperature tolerant methanogens which were selected for use as inoculum for anaerobic fermentation of agricultural and livestock wasted at low temperature. The results, obtained were summarized as follows: Low temperature tolerant methanogens were isolated from the samples which showed the high methanogenesis rate by enrichment culture at low temperature in methanol medium. These methanogens, Methanobacterium M-251 and Methanobacterium M-253 were isolated from swampy sediment at latitude $56.9^{circ}$, Methanosarcina mazei M-372 from lake sediment IV at latitude $55.0^{circ}$ N, and Methanobacterium formicicum M-375 from tidal land soil at latitude $37.0^{circ}N$, respectively. The isolated anaerobic bacteria could not use sugars as carbon sources. The optimum pH value for the growth of M-251 and M-375 was 6.8, but those for M-253 and M-372 6.5 and 7.0, respectively. The minimum growth temperature of isolated, M-251 and M-253 were $8^{circ}C$ and the optimum temperature $30^{circ}C$, while the minimum of M-392 and M-395 were $13^{circ}C$ and the optimum $37^{circ}C$. The growth rate of isolates at $17.5^{circ}C$ were lower by 32-50% than that of $30^{circ}C$. The isolated Methanobacterium strains such as M-251, M-253, and M-375 have lower cell yield, 0.38-1.21g/1M $CH_4$ than 1.14-1.51g/1M $CH_4$ of Methanosarcina mazei M-372.