Laboratory incubation experiments were conducted to study the effects of soil chemical and physical properties on CH4 emission and entrapment in 16 selected soils with a p H range of 4 . 7 -8 . 1 , organic matter content o f 0 . 7 2 -2 . 3 8 % , and soil texture from silt to clay. There was no significant correlation with C H 4 emission for most o f the important soil properties, including soil aerobic p H (measured before anaerobic incubation), total Kjeldahl N, cation exchange capacity, especially soil organic matter, and soil water-soluble C, which were considered to be critical controlling factors o f C H 4 emission. A lower CH4 emission was observed in some soils with a higher organic matter content. Differences in soil Fe and M n contents and their chemical forms contributed to the this observation. A significant correlation between the C H 4 emission and the soil organic C content was observed only after stratifying soils into subgroups according to the level of C H 4 emission in soils not amended with organic matter. The results also showed that the soil redox potential (Eh), anaerobic pH, anerobic pH, and biologically reducible Fe and Mn affected CH4 emission significantly. Urea fertilization promoted C H 4 emission in some soils and inhibited it in others. This result appeared to be related to the original soil pH. C H 4 entrapment was positively correlated with soil clay content, indicating the importance of soil physical characteristics in reducing C H 4 emissions to the atmosphere.