A duct cap assembly for a refrigerator, comprising: a duct cap configured to open and close an ice duct formed in the refrigerator; an opening and closing mechanism configured to open and close the duct cap; and a damper assembly connected to one of the duct cap and the opening and closing mechanism, wherein the damper assembly delays a closing operation of the duct cap upon initiation of a closing operation, wherein the damper assembly comprises: a cylinder having an open end and a closed end, and including a small diameter region and a large diameter region; a packing holder disposed to be movable within the cylinder; a packing installed in the packing holder; and a connecting rod connected to the packing holder and one of the duct cap and the opening and closing mechanism, wherein the packing holder comprises: an inner holder having connection portions (122, 123) projected therefrom, the connection portions (122, 123) being connected to the connecting rod; and an outer holder having a through-hole through which the connection portions (122, 123) are passed, wherein the packing is disposed between the inner holder and the outer holder, wherein the packing is formed of a flexible material and comprises: an outer circumference having an inclined portion formed extending therefrom, the inclined portion including an outer surface, a vertical surface, and an inner surface, wherein when the packing is moved toward the closed end of the cylinder, the outer surface of the inclined portion rubs against or comes into frictional contact with the inner surface of the small diameter region of the cylinder and the inclined portion is not deformed or is slightly contracted in an inner-radial direction such that the packing is quickly inserted into the small diameter region without great resistance; and when the packing is moved toward the open end of the cylinder, the vertical surface and/or the inner surface of the inclined portion rubs against or comes into frictional contact with the inner surface of the small diameter region, and the inclined portion is widened in an outer-radial direction by high friction generated between the packing and the small diameter region such that the packing is slowly drawn out of the small diameter region; an inner circumference having a smaller diameter than the outer circumference; a front surface connecting the outer circumference to the inner circumference, and a ring-shaped space formed between the outer circumference and the inner circumference, characterized in that the outer holder has at least one insertion rib configured to be inserted into the ring-shaped space of the packing. a duct cap configured to open and close an ice duct formed in the refrigerator; an opening and closing mechanism configured to open and close the duct cap; and a damper assembly connected to one of the duct cap and the opening and closing mechanism, wherein the damper assembly delays a closing operation of the duct cap upon initiation of a closing operation, a cylinder having an open end and a closed end, and including a small diameter region and a large diameter region; a packing holder disposed to be movable within the cylinder; a packing installed in the packing holder; and a connecting rod connected to the packing holder and one of the duct cap and the opening and closing mechanism, an inner holder having connection portions (122, 123) projected therefrom, the connection portions (122, 123) being connected to the connecting rod; and an outer holder having a through-hole through which the connection portions (122, 123) are passed, wherein the packing is disposed between the inner holder and the outer holder, an outer circumference having an inclined portion formed extending therefrom, the inclined portion including an outer surface, a vertical surface, and an inner surface, wherein when the packing is moved toward the closed end of the cylinder, the outer surface of the inclined portion rubs against or comes into frictional contact with the inner surface of the small diameter region of the cylinder and the inclined portion is not deformed or is slightly contracted in an inner-radial direction such that the packing is quickly inserted into the small diameter region without great resistance; and when the packing is moved toward the open end of the cylinder, the vertical surface and/or the inner surface of the inclined portion rubs against or comes into frictional contact with the inner surface of the small diameter region, and the inclined portion is widened in an outer-radial direction by high friction generated between the packing and the small diameter region such that the packing is slowly drawn out of the small diameter region; an inner circumference having a smaller diameter than the outer circumference; a front surface connecting the outer circumference to the inner circumference, and a ring-shaped space formed between the outer circumference and the inner circumference,