Landfill site is one of the most important sources of greenhouse gas emissions. The available information shows that greenhouse gas emissions from the landfill sites are 40% 50% of the total greenhouse gas emissions in America. The greenhouse gas output is computed in the text and the conclusion that the main components of yielding gas are food and paper is made. Some measures of cutting greenhouse gas yielding are suggested. At last it points out that some research about these measures should be made in the future in China.