A protection cover support seat structure for tablet display apparatus includes a support member, a display adjustment seat and a connection assembly. The support member has a first end section and a second end section opposite to the first end section. The display adjustment seat is pivotally connected to the first end section via at least one first pivot member. An engagement locating assembly with elastic engagement function is disposed between the display adjustment seat and the connection assembly. One side of the connection assembly is connectable with the tablet display apparatus. The second end section is pivotally connected with a base seat, which is further pivotally connected with a board body. Accordingly, the tablet display apparatus can be co-used with the board body and rotated and tilted by different angles and supported in an inclined position in adaptation to different use situations and requirements.