Following Fama and French's (1992, 1993) findings that firm characteristics or factors such as size and value have forecasting power for excess returns, academics and the financial industry are investigating and investing in styles of value and growth. The literature examining the value premium (the excess performance of value portfolio over growth portfolio) typically focuses on long-term performances in international stock markets, including the Korean stock market. In addition, according to the literature, participants such as institutional investors avoid investing in growth stocks. However, many empirical studies indicate that the value premium is related to the current state of the economy. They argue that value premiums are time-variant. Therefore, we analyze the existence of value premiums and the performance of style allocation strategies across different regimes in Korean stock market. We use style indices data for the Korean stock market developed by three indices companies, FnGuide, WISEfn, and MSCI, comprising three value indices and three growth indices from 2001 to 2014. Although value indices outperform growth indices for three indices companies during the total sample period, the outperforming of styles is not stable over time. That is, the sign and degree of the value premium varies each year. This time-varying value premium suggests that style allocation strategies to spread investment across value and growth stocks outperform strategies to invest only in value stocks. Thus, to construct a dynamic style allocation strategy based on stock market regimes, we identify two regimes using the regime-switching model introduced by Hamilton (1989, 1990) using the KOSPI index. The first regime based on the KOSPI index has high average returns and low volatility—this is the expansion regime or low-volatility regime. The second regime has low average returns and far high volatility—this is the recession regime or high- volatility regime. According to the result from the regression analysis regarding value and growth indices, growth stocks strongly outperform value stocks in low-volatility regimes. Our strategy is to adjust the weight between the value portfolio and the growth portfolio constructed on different regimes to show better performance over value-only investment strategy. In particular, the performance of dynamic style allocation strategy is best when we use the value index and growth index of MSCI. This result comes from the better performance of growth indices over value indices during the expansion regime (or low-volatility regime). The style allocation strategy that adjust the weights of growth stocks and value stocks of MSCI in different regimes or according to the probabilities of regimes shows an annual average return of 13.86% (in-sample) and 14.09% (out-of-sample), while the strategy to invest only in value stocks of MSCI earns an annual average return of 12.86%. That is, the dynamic style allocation strategy using MSCI indices produces 1.0% (in sample) and 1.23% (out-of- sample) more per annum than the value-only investment using the MSCI value index. Furthermore, for all three companies, the style allocation strategy outperforms the value-only investment over a considerable period. In particular, it is important to properly adjust the portfolio weights of styles in the large-value premium period. The style allocation that profits promoted in 2004 and 2012 as styles are rotated appropriately according to the regimes. In 2008 and 2014, when the returns on growth stocks were relatively high, the style allocation profits developed due to the increasing investment weight of the growth index. Note that the style allocation performance using MSCI indices is best and has the strongest correlation across the three indices companies. We expect that the style allocation can produce higher returns when we use data that have clearer characteristics or style, such as pure-value- and pure-growth- oriented funds. In conclusion, we identify the time-varying value premium in the Korean stock market. A proper style allocation strategy based on the economic situation or market conditions can generate better performance than investments that exclude growth stocks.