Previous studies have shown there are substantial differences between short-run and long-run performances of firms in post-IPO. The firm value also undergoes obvious changes depending on their industries. This paper examines the relationship between IPO age and P/B ratio for the Taiwanese LED industry. The effective sample consists of 26 firms with 533 sample observations with regards to their IPO between 2001 and 2007. The empirical results finds (1) In the Taiwanese LED industry, a firm's position in the industry value chain, and the IPO age jointly affect the P/B ratio. (2) The long-run performance is not always worse than the short-run performance after the LED firm's IPO. The performance depends on the firm's position in the industry value chain. For upstream firms, P/B ratio will increase significantly along with the increasing IPO age. For mid and downstream firms, P/B ratio decreases slowly as time passes with the IPO. These characteristics could be related to the integration and synergy of industry clusters, or as the result of different evaluations by investors towards different products along the value chain at different stages of the product life cycle. The results indicate that the accumulation of experience and skills directly influence the firm's value depending on their role in the value chain, and indirectly influence the development of the entire LED value chain.