Korean business enterprises suffered from the dramatic changes of GAAP in the process of overcoming the crisis of IMF foreign currency occurred in 1997. Among them, accounting for the research and development(R&D) costs was also an significantly controversial issue. Before 1998 in Korea, extraordinary portion of the R&D costs was treated for the deferred charges, and ordinary portion of them was treated for the current expenses. This accounting standard results in reporting some research costs as assets that have much more uncertainties in future economic benefits than development costs owing to not dividing the R&D costs into the two different components. After 1998, Korean accounting standards for the R&D costs tighten the requirements of recognition of R&D costs as assets, dividing the R&D costs into research costs and developments and then recognizing all of the research costs as current expense. For the extraordinary portion of development costs, they tighten the requirements of recognition of the costs as assets and coincide Korean accounting standards with the international accounting standards. As above described, Korean GAAP mandates the selective capitalization of R&D in financial statements and also strengthens the requirements of capitalization through the 1998 revision of GAAP, presumably because of concerns with both the reliability and valuerelevance of R&D capitalization. To address these concerns, we provide evidence on the potential informational benefits of selectively capitalizing and amortizing R&D costs and strengthening the requirements of recognition of R&D costs as assets by comparing the extent to which reported earnings and book values explain the distribution of share prices between before 1998 and after 1998. In the first place, this study examines the impact of alternative accounting schemes(immediate expensing, full capitalization, selective capitalization) for R&D costs on the extent to which earnings and book values jointly explain the observed distribution of share prices and see if the usefulness of accounting information by selective capitalization of research and development costs under current accounting standards is the highest with explanatory power(Adj-R ) of share prices. Next, this study examines whether usefulness of accounting information by selective capitalization with the revision of GAAP of 1998 is improved in explaining the volatility of share prices. The sample size of this study is 3,718 firms-years. We selected as sample firms non-banking firms with the December fiscal year-end listed in the Korean Stock Exchange over 1994-2003. The main results are summarized as follows. First, we find that explanatory power of R&D costs information by full capitalization(10 amortization period) was the highest among the alternative accounting schemes for R&D costs. Because current selective capitalization is the voluntary accounting by CEO's discretionary power and selective capitalization rate(SCR) is so low, the effects of theoretical selective capitalization do not appear sufficiently. Second, we find that explanatory power of R&D accounting information by selective capitalization was significantly lower after revision(1999～2003) than before revision(1994∼ 1998) surrounding the 1998 revision of GAAP. The decrease of explanatory power by selective capitalization is probably due to the significant decrease of selective capitalization rate which was driven by more conservative requirements of selective capitalization of R&D costs. Consequently, this results suggest that capitalization requirements of development costs should be moderated and more R&D costs should be capitalized. The previous research on the accounting for the R&D costs in Korea also concluded that the ordinary portion as well as the extraordinary portion of development costs is qualified for the recognition of assets Based on the change of explanatory power of the selective capitalization with the size of selective capitalization rate, we estimate the Korean selective capitalization curve(KSC).