The composition of MSW is closely related to the level of economic development and lifestyle of the residents. In different districts of the same city, the composition of MSW will be different. On the whole,the composition of MSW in China is as follows: the moisture content of MSW varies with the district and the season, but is normally more than 40%–50% (Tables 2–4); organic materials (food scraps, leaves, grass, wood, and animal matter) and packaging make up more than 50% on a dry-weight basis; the ash and dust content is 10%–20% on a dry-weight basis. The majority of waste paper, waste metal, waste containers, and waste plastic is separated and sold to private collectors, so the proportion of recoverable materials has not increased. Figure 2 shows the composition of MSW in China, and Table 5 shows the composition of MSW coming from different sources in Beijing