A wiper blade and wiper arm connecting structure for connecting a wiper blade to a wiper arm by fitting a connecting portion of the wiper blade into a coupling portion of the wiper arm, the coupling portion including an opening for introducing the connecting portion into the coupling portion, the coupling portion including a locking portion disposed adjacent to the opening, the connecting portion including an elastically deformable locking piece, and the locking piece including a locking recess portion into which the locking portion is fitted, wherein the coupling portion includes a top wall and a pair of side walls, the opening being disposed at a distal end of the coupling portion, the connecting portion being fitted into a housing portion surrounded by the top wall and the side walls through the opening, wherein the locking portion of the coupling portion is formed at a distal end of the top wall, wherein the connecting portion is a member including a main body portion having a substantially rectangular parallelepiped shape to which the coupling portion of the wiper arm is installed and a front end portion which has a streamline shape and is provided at the front side of the main body portion, the main body portion including an upper wall and a pair of side portions provided on both sides of the main body portion, characterized in that the locking piece is formed by cutting out the upper wall of the main body portion and extends forwardly from a proximal end portion which is a fixed end to a distal end portion which is a free end, the proximal end portion extending from the proximal end side of the upper wall, wherein a protruding portion protruding upwardly is provided at the rear side of the distal end portion of the locking piece, wherein the locking recess portion is formed between the distal end portion and the protruding portion, and wherein when the coupling portion and the connecting portion are connected, the connecting portion is introduced into the opening of the coupling portion from the side facing a rear end of the main body portion and the locking portion of the coupling portion arrives at the protruding portion of the locking piece and depresses the locking piece downwardly and wherein when the connecting portion is completely housed in the coupling portion, the locking portion fits into the locking recess portion of the locking piece so that the coupling portion is locked on the connecting portion. the coupling portion including an opening for introducing the connecting portion into the coupling portion, the coupling portion including a locking portion disposed adjacent to the opening, the connecting portion including an elastically deformable locking piece, and the locking piece including a locking recess portion into which the locking portion is fitted, wherein the coupling portion includes a top wall and a pair of side walls, the opening being disposed at a distal end of the coupling portion, the connecting portion being fitted into a housing portion surrounded by the top wall and the side walls through the opening, wherein the locking portion of the coupling portion is formed at a distal end of the top wall, wherein the connecting portion is a member including a main body portion having a substantially rectangular parallelepiped shape to which the coupling portion of the wiper arm is installed and a front end portion which has a streamline shape and is provided at the front side of the main body portion, the main body portion including an upper wall and a pair of side portions provided on both sides of the main body portion, characterized in that the locking piece is formed by cutting out the upper wall of the main body portion and extends forwardly from a proximal end portion which is a fixed end to a distal end portion which is a free end, the proximal end portion extending from the proximal end side of the upper wall, wherein a protruding portion protruding upwardly is provided at the rear side of the distal end portion of the locking piece, wherein the locking recess portion is formed between the distal end portion and the protruding portion, and wherein when the coupling portion and the connecting portion are connected, the connecting portion is introduced into the opening of the coupling portion from the side facing a rear end of the main body portion and the locking portion of the coupling portion arrives at the protruding portion of the locking piece and depresses the locking piece downwardly and wherein when the connecting portion is completely housed in the coupling portion, the locking portion fits into the locking recess portion of the locking piece so that the coupling portion is locked on the connecting portion.