We propose a simple way to capture the multidimensionality of liquidity. Our analysis indicates that existing liquidity measures have considerable asset specific components, which justifies our new approach. Constructing a two-factor model with the market and liquidity factor proposed in this paper, we find that our two-factor model well explains the cross-section of stock returns in Korea during 1987~2010, describing the liquidity premium, size and value effects that the CAPM and Fama-French three-factor model fail to explain. Our results also show that the role of liquidity risk on expected stock returns is especially pronounced during the post-Asian financial crisis period.