Petrleum resin is a C5/C9 aromatic hydrocarbon used in industrial applications. It has a tackifying effect and is suitable for use in paint, printing ink, adhesives, rubber and other areas where tackiness is required. It is a kind of thermal plasticizing hydrocarbon resin produced by C5, C9 fraction, by-products of petroleum cracking, through pretreatment, polymerization and distillation. It is not a high polymer but a low polymer with the molecular weight between 300-3000. Featured by acid value, easy mutual solubilities, resistant to ethanol and chemicals. It has the chemical stabilizing property to acid and alkaline, viscocity adjusting and thermal stabilizing. Generally, the petroleum resins are not used independently, but have to be used together with other kinds of resins as per promoters, adjusting agents and modifiers in hot-melt adhesive, pressure-sensitive adhesive, hot melt road marking paint, rubber tires and so on.