A method of screen content coding (SCC) and video coding using coding modes including IntraBC mode (Intra-block copy mode) is disclosed. In one embodiment, a Merge candidate list including one or more IntraBC Merge candidates and one or more Inter Merge candidates is derived. If an IntraBC Merge candidate is selected from the Merge candidate list for the current block, the current motion information of the current block is encoded or decoded by sharing candidate motion information of the selected IntraBC Merge candidate as the current motion information of the current block, and the current block is encoded or decoded using a coded block in the current picture located according to the current motion information as an IntraBC predictor. The candidate motion information or the current motion information may include one or more elements selected from a motion information group consisting of coding mode, displacement vector and reference picture information.