This chapter discusses pyrolysis process for the separated waste plastics and for the upper siftings of aged Municipal solid waste (MSW) were compared by checking the yield and quality of the products to improve the pyrolysis process. The pyrolysis tests were carried out for the whole combustibles and for the separated waste plastics from aged MSW at lab scale. Pyrolysis produces high calorific value fuels with lower emissions in the process, the produced fuels could be easily used for power generation and heat supply, especially as pyrolysis process carried out for waste plastics, and high quality oil can be obtained. The proximate analysis of pyrolysis solid residues was carried out on according to GB212-2008, the standard proximate analysis method of coal. The expected liquid product from separated plastics is twice of that from upper siftings, and the un-expected solid product is much lower for plastics.