The purpose of this study is to develop a theoretical model linking accounting beta and market beta, to empirically analyze this model using data from the Korean securities market, and to evaluate the predictive ability of the developed model for future market beta. In this study, accounting beta was first defined using Equations (2-4), (2-13), and (2-14), and then the theoretical relationship equations between accounting beta and market beta were derived as Equations (2-10), (2-17), and (2-20). The empirical analysis of the relationship equations presented in this study showed that the test models were statistically significant across all investigation periods, indicating that as all accounting betas presented in this study increase (decrease), market beta also increases (decreases). Meanwhile, the evaluation of the models' predictive ability for future market beta revealed that the predictive ability of the models was far superior to the predictive ability obtained by simply using the market beta from the first period.