Abstract: From June, 2007 to October, 2009, a measurement with static chamber / gas chromatograph techniques was conducted on the soil CH₄ flux in a typical secondary hardwood forest in Northeast China under the effects of different harvest disturbances, i.e., uncut (control), clear cutting (including both farming and reforestation after clear cutting), 50% stand volume removed, and 25% stand volume removed. In all of the four treatments, the soil was the sink of atmospheric CH₄, but cutting decreased the soil CH₄ uptake flux, with the order of uncut (-85.03 μg CH₄·m^-2·h^-1) > 50% stand volume removed (-80.31 μg CH₄·m^-2·h^-1) > 25% stand volume removed (-70.97 μg CH₄·m^-2h^-1) > farming after clear cutting (-65.57 μg CH₄·m^-2·h^-1) > reforestation after clear cutting (-62.02 μg CH₄·m^-2·h^-1). During the study period, the seasonal patterns of the soil CH₄ uptake flux in all treatments were similar, with a higher value in growth season and a lower one in winter. After the harvest disturbance, the soil temperature, humidity, and NO₃^--N, and NH₄⁺-N contents were all increased, and the soil CH₄ flux had a significant quadratic correlation with soil temperature, and a negative linear correlation with soil moisture content. It was suggested that the increase of the soil moisture, NO₃^--N, and NH₄⁺-N contents after the forest harvest was the main cause of the decrease of the soil CH₄ uptake flux.