In VTM4.0, Intra Sub-Partitions (ISP) method requires two additional 6 MPM list construction processes (one for horizontal split mode and the other for vertical split mode) to derive the intra mode candidates. This contribution proposes to remove the two additional 6 MPM lists construction process which are dedicated to ISP mode, and to assign a default intra prediction mode list based on ISP split mode. More precisely, planar and horizontal intra mode are assigned for horizontal split mode, and planar and vertical intra mode are assigned for vertical split mode.