Polyvinyl chloride (PVC) is one of the major synthetic resins, and is widely used in the building, packing, and automobile industry. Additives such as calcium carbonate (CaCO3) and di-n-octyl phthalate (DnOP) are often added in production of plastics to improve the properties of plastics or lower the cost [14], [15] and [16]. Based on our previous study, additives have certain impacts on the flotation behavior of waste plastics [17]. From preliminary tests, it was found that there were significant differences in the flotability of PVC plastics in various application areas. The natural flotability is defined as the flotation recovery when flotation tests are conducted without reagents. This paper focuses on the effects of additives on the surface of PVC plastics and further investigates the natural flotability of PVC plastics.