Abstract: The present disclosure provides a seat cover for car back seats. The seat cover includes a back portion and a seat portion connected with the back portion. The back portion includes a first back unit configured to cover one back seat and a second back unit configured to cover another one back seat. The first back unit and the second back unit are in a detachable connection. A detachable gap is located between the first back unit and the second second back unit during the first back unit and the second back unit detached from each other. The detachable gap is used for the seat belt and the seat armrest protruding through. A protruding space is located between the first back unit and the second back unit, and the protruding space is configured to accommodate a seat belt and a seat armrest protruded out from the car back seats.