Provided are a method and apparatus for entropy-encoding/entropy-decoding video data. The method of entropy-encoding video data includes binarizing coefficients of the frequency domain, which are generated by transforming a residual block of a current block into the frequency domain, using different binarization methods and performing binary arithmetic coding on the binarized coefficients. In this way, the coefficients are binarized adaptively according to whether the frequencies of the coefficients are high or low, thereby improving the compression efficiency of the video data.