Formosa Plastics Corporation was founded in 1954. At start-up in 1957, its plant produced 4 MT/day of polyvinyl chloride (PVC) resin, the smallest PVC plant in the world at that time.  With Such a small production volume, product costs were comparatively high. Due to the lack of a local downstream industrial base, sales remained stagnant, resulting in the stockpiling of finished goods. To ameliorate this situation, it was decided to increase production volume in order to lower unit costs. PVC production volume went up from 4 MT/day to 40 MT/day.

At the same time, plans were made to construct downstream processing facilities to help consume the PVC resins. Nan Ya Plastics Corporation was set up in 1958 to produce secondary products such as PVC pipes, PVC film, and plastic leather. Soon afterwards, the New Eastern Corporation was formed to help consume Nan Ya's products by making such tertiary products as handbags, luggage, shoes, curtains, raincoats, and blow-molded toys, for the export market. 

The strategy was enormously successful in solving the problem of slow sales of PVC resins. With the following expansions of Formosa Plastics Group and development of new businesses by its ex-employees, an enormous tertiary processing industry was created, with no rival in the world. This led to the prosperous development of the local petrochemical industry and contributed significantly to the economic development of Taiwan. 

The Formosa Plastics Group diversified into the textile industry in 1965. It set up Formosa Chemicals and Fibre Corporation (FCFC) to produce rayon staple fiber, yarn, fabric, and garments, from the discarded wood left on the mountains after lumbering. Nan Ya expanded in 1967, setting up plants to produce polyester staple fiber. The same year Formosa Plastics Corporation set up plants to produce acrylic fiber. In 1974 FCFC added nylon filament and fabric to its product lines. To offer better service to downstream customers, large-scale dyeing and finishing plants were set up to add to the value of the textile products. The companies were the only ones in Taiwan that produced four kinds of fibers and offered finishing and dyeing services. The Formosa Plastics Group had become one of the largest fiber producers in the world.

In view of the rapid development of the electronics and information industries in Taiwan, Chairman Wang saw a way to reduce dependence on imports of major components. Although unfamiliar with the electronics industry, Nan Ya selected and began investing in 1984 in the manufacturing of printed circuit boards and copper-clad laminates. The printed circuit board is one of the basic components of the industry, with a long product life and few variations. The key to success would lie in the control of manufacturing processes and costs, which is the management expertise of the Group. Once familiar with the business operations of the industry, the Company would seek future expansions.

Taiwan's chronic shortage of upstream petrochemical materials, at a self-sufficiency rate of merely 38%, forced the middle and downstream manufacturing industries to rely on more expensive imports and dampened their competitiveness in the international markets. Formosa Plastics proposed the No. 6 Naphtha Cracker Project to alleviate the shortage problem. The government's approval was obtained in 1986. In coordination with this giant undertaking, Formosa Petrochemical Corporation was founded in 1992 to take charge of the construction of the oil refinery, naphtha cracking plant, and co-generation plant. The first phase of the oil refinery as well as the projects of the naphtha cracking plant and co-generation plant have already been completed. This achievement, and the continuous output from petrochemical related factories of affiliated companies, has already realized the value of vertical integration of the No. 6 Naphtha Cracker Project and has advanced the operational abilities of the group as a whole.

With over 40 years of development, the Formosa Plastics Group is now the largest private enterprise in Taiwan. The Group includes Formosa Chemicals &Fibre Corporation, Formosa Petrochemical Corporation, and more than 20 other investments in Taiwan, the united States, China, and Indonesia, in addition to several large educational and medical organizations.