The importance of intangible assets have increased unprecedentedly with the advent of the knowledge-based society. Investment in R&D has contributed to the rise of productivity and firm-value in the capital markets. but it is very difficult to determine the economic benefits of R&D investment, due to elusive link between time requirements and the realization of firm value from R&D investment. This study examines the differential effects of R&D expenditure and patents on firm-value by industry. Patents are intangible, proprietary rights that develops new products, plays a crucial role in market competition and results in research and development activities. If firms get patents, their R&D expenditure is assumed to be successful. The study analyzes whether successful R&D expenditure has a significant effect on the firm-value. The study considers two industries : high-tech industries and low-tech industries. These industries are expected to have different effect on R&D expenditure and firm-vale. The results of the study indicate that the successful R&D expenditure increased the firm-value. Successful R&D expenditure in high-tech industries more increased the firm-value more than that in low-tech industries