A portfolio includes a body having a receiving space therein, a backside of the body having at least one sliding groove, an upper cover being a foldable sheet for sealing the receiving space; and a connecting unit passing through the sliding groove of the body and the upper cover so that the upper cover is slidable along the body. The connecting unit is a T rod and a washer; the T rod passes through a through hole of the upper cover and the sliding groove of the body, an enlarged end of the T rod resists against an upper side of the through hole; a size of the enlarged end of the T rod is greater than the size of the through hole and the sliding groove so that the T rod is retained upon the rear surface; and another end of the T rod is engaged with a washer.