A needle protection device, comprising: a connecting portion configured to engaged with a needle hub of a needle; a protection arm configured to receive a needle tube of the needle therein and having a proximal end portion adjacent to the connecting portion; a hinge member connected between the connecting portion and the protection arm so that the protection arm is rotatable relative to the connecting portion; a pair of holding members (51, 52) formed on the proximal end portion of the protection arm and the connecting portion respectively, wherein the pair of holding members (51, 52) are configured to be engaged with each other in an unretreatable manner when the protection arm rotates to a full protection position in which the protection arm is most approximate to the needle tube of the needle relative to the connecting portion, characterized in that the pair of holding members (51, 52) comprise: a first holding member comprising a first column-like portion and an anchor formed on the first column-like portion; and a second holding member comprising one or more paws formed on an edge of a through hole and extending towards a center of the through hole, distal ends of the paws, or the distal ends of the paws and the edge of the through hole, defining a bore which has a maximum radial dimension of the bore smaller than a maximum radial dimension of a base of the anchor, wherein the paws are configured such that the distal ends of the paws allow a front end of the anchor to pass through the through hole and catch the base of the anchor in an unretreatable manner when the protection arm rotates to the full protection position. a connecting portion configured to engaged with a needle hub of a needle; a protection arm configured to receive a needle tube of the needle therein and having a proximal end portion adjacent to the connecting portion; a hinge member connected between the connecting portion and the protection arm so that the protection arm is rotatable relative to the connecting portion; a pair of holding members (51, 52) formed on the proximal end portion of the protection arm and the connecting portion respectively, wherein the pair of holding members (51, 52) are configured to be engaged with each other in an unretreatable manner when the protection arm rotates to a full protection position in which the protection arm is most approximate to the needle tube of the needle relative to the connecting portion, characterized in that the pair of holding members (51, 52) comprise: a first holding member comprising a first column-like portion and an anchor formed on the first column-like portion; and a second holding member comprising one or more paws formed on an edge of a through hole and extending towards a center of the through hole, distal ends of the paws, or the distal ends of the paws and the edge of the through hole, defining a bore which has a maximum radial dimension of the bore smaller than a maximum radial dimension of a base of the anchor, wherein the paws are configured such that the distal ends of the paws allow a front end of the anchor to pass through the through hole and catch the base of the anchor in an unretreatable manner when the protection arm rotates to the full protection position. a first holding member comprising a first column-like portion and an anchor formed on the first column-like portion; and a second holding member comprising one or more paws formed on an edge of a through hole and extending towards a center of the through hole, distal ends of the paws, or the distal ends of the paws and the edge of the through hole, defining a bore which has a maximum radial dimension of the bore smaller than a maximum radial dimension of a base of the anchor, wherein the paws are configured such that the distal ends of the paws allow a front end of the anchor to pass through the through hole and catch the base of the anchor in an unretreatable manner when the protection arm rotates to the full protection position.