In a method and apparatus for predictive Intra coding of a non-square block using modified mode-dependent coefficient scanning (MDCS), the modified MDCS is derived from the MDCS that is designed for a square block. The mapped Intra modes for the non-square block are derived by mapping the Intra modes for the square block to the mapped Intra modes for the non-square block. The mapped Intra modes are divided into multiple groups including a first modified angular group and a second modified angular group. The modified MDCS modifies the number of the mapped Intra modes in the first modified angular group or the second modified angular group by comparing an angle spanned by the mapped Intra modes in the first modified angular group or the second modified angular group with the angle spanned by the corresponding Intra modes of the conventional MDCS.