A method and apparatus for video coding including an Intra transform Skip mode is disclosed. When the transform Skip mode is ON for a transform unit, embodiments according to the present invention apply different coding processes to the transform unit. The coding process with the transform Skip mode ON uses a different scan pattern from the coding process with the transform Skip mode OFF. According to various embodiments, the transform Skip mode is enabled when the transform unit size is 4×4, the prediction unit and the transform unit having the same size, or the prediction unit uses an INTRA_N×N mode. When the transform Skip mode is enabled, a flag can be signaled in the bitstream to indicate the transform Skip mode selection. Furthermore, the flag can be incorporated in a picture level, a slice level or a sequence level of the video bitstream.