A, PX–PTA PX is the from the raw materials mixed xylene (MX) separated, mixed xylene mainly made up of p-xylene, o-xylene and xylene. Mixed xylene primarily come from the coking industry, now mainly from the petrochemical industry. Coking of p-xylene production is very small, only 2% per cent of total output, and almost all as mixed xylene used directly without separation. PX production outside PTA uses, also used as a solvent and as a pharmaceutical, perfumery, production of raw materials such as ink, but a very small percentage of the total consumption. Therefore, the PX mixer that can be referred to as polyester products chain, is an important chemical raw materials, PX effect of price changes on the PTA are very large. Before 2003 most PX can be self-contained, but with the PTA private and joint-venture in China in recent years new projects coming on stream, 2005 has become the world’s biggest PTA producer in China, growth of demand for PX, PX 2003 China imports exceeded 1 million tons, in 2006, China as the world’s largest consumer of PX. Second, the MEG–polyester raw material ethylene glycol (EG) also known as glycol, ethylene glycol, include ethylene glycol, diethylene glycol, triethylene glycol. Commonly referred to as glycol ethylene glycol (MEG), ethylene oxide, CO2 and water produce carbonic acid ethyl esters (EC) and hydrolysis are ethylene glycol (MEG). Ethylene glycol is an important oil based organic chemical raw materials, mainly for the production of polyester fiber resin, unsaturated polyester, antifreeze, lubricant, plasticizer, non-ionic surfactants, such as explosives, also used in coatings, photographic developer fluid, brake fluid and ink industry, very wide application. About 75% for the production of polyester fiber in global output of MEG, 15% used in the production of polyester resin (mainly used in paint), 10% used in antifreeze, surface coatings and other purposes. China is the world’s largest polyester producers, in 2005 China’s total capacity per cent of total world production of pet 40%, MEG consumption in China accounted for consumption of Asian MEG one-second, over 30% of worldwide MEG consumption. In 2005 MEG only 1.516 million tonnes of production capacity in China, accounted for only about MEG 15% of the total production capacity in Asia, around 8% per cent of total production capacity of MEG in the world. Three-polyester, polyester–PTA products (PET) by the PTA and MEG aggregation becomes. PET is a grain-like, species diversity. Among them, 75% used in chemical fiber polyester, manufactured of polyester staple fiber and polyester filament, 20% on a bottle-grade pet (widely used in the packaging of various beverages, especially carbonated beverages), 5% for polyester films (mainly used in packaging materials, films and tapes). From 2001 to 2005, average productivity of China polyester to 24% growth rate of expansion is far better than the 10% of the world increases, until the end of 2005 the total capacity of polyester in China exceeded 20 million tons. Four-terminal product, polyester–PTA according to the requirements of the textile industry, two of polyester fiber filament and staple fiber. Polyester fibers for clothing, fabric, after washing it not to crease-free ironing effect. Polyester industry can be used to transfer belt, tents, canvas and rope, fishing nets, especially made of polyester tire cords, performance is close to nylon. Pet is also used for electrical insulation materials, acid-resistant filter cloth, cloth of the pharmaceutical industry. In 2005, our polyester production of 12.7 million tons, output of polyester slice of 5.14 million tons. As the industrial chain of the end product, polyester on the amount of PTA reaches a total of 70%, therefore, PTA fluctuations directly affected the price of polyester production costs.