A front cover structure for ef a motorcycle, comprising a front cover covering the front portion of a vehicle body; a duct provided inside the front cover and guiding the traveling wind from the front side; wherein the front cover has an upper portion provided above a front wheel and a side portion extended downward from both side portions of the upper portion in the width direction of the vehicle; and said duct has an intake port, said intake port has a longitudinal intake port provided on the front end of said side portion and opened vertically and longitudinally, and an oblong intake port provided on the lower end of said upper portion and opened horizontally and longitudinally from the upper end of said longitudinal intake port to the inside in the width direction of the vehicle; the intake port is located in the front end of the front cover and the oblong intake port and the longitudinal intake port are integrally formed to be formed in L-shape in the front view; characterized in that said front cover has a front inner cover covering the front portion of said vehicle body formed inside the front cover, and a front outer cover covering the outside of the front inner cover from the outside in the width direction of the vehicle, said duct is formed between said front outer cover and said front inner cover by covering said front inner cover with said front outer cover, and said front inner cover is formed so as to be extended to the inner direction of said oblong intake port in the width direction of the vehicle and has a guide portion guiding the traveling wind to said longitudinal intake port, and the duct extends in the front and rear direction, wherein the duct becomes from the L-shape to a rectangular-shape in the vicinity of the middle of the duct, a distance in the height direction in the vicinity of the middle of the duct is smaller than distance in the height direction in the vicinity of the intake port of the duct, a passage area in the vicinity of the middle of the duct is smaller than a passage area in the vicinity of the intake port of the duct, and a distance in further backward than the duct is smaller than the distance in the height direction in the vicinity of the middle of the duct, a passage area in further backward than the duct is smaller than the passage area in the vicinity of the middle of the duct. a front cover covering the front portion of a vehicle body; a duct provided inside the front cover and guiding the traveling wind from the front side; wherein the front cover has an upper portion provided above a front wheel and a side portion extended downward from both side portions of the upper portion in the width direction of the vehicle; and said duct has an intake port, said intake port has a longitudinal intake port provided on the front end of said side portion and opened vertically and longitudinally, and an oblong intake port provided on the lower end of said upper portion and opened horizontally and longitudinally from the upper end of said longitudinal intake port to the inside in the width direction of the vehicle; the intake port is located in the front end of the front cover and the oblong intake port and the longitudinal intake port are integrally formed to be formed in L-shape in the front view; characterized in that said front cover has a front inner cover covering the front portion of said vehicle body formed inside the front cover, and a front outer cover covering the outside of the front inner cover from the outside in the width direction of the vehicle, said duct is formed between said front outer cover and said front inner cover by covering said front inner cover with said front outer cover, and said front inner cover is formed so as to be extended to the inner direction of said oblong intake port in the width direction of the vehicle and has a guide portion guiding the traveling wind to said longitudinal intake port, and the duct extends in the front and rear direction, wherein the duct becomes from the L-shape to a rectangular-shape in the vicinity of the middle of the duct, a distance in the height direction in the vicinity of the middle of the duct is smaller than distance in the height direction in the vicinity of the intake port of the duct, a passage area in the vicinity of the middle of the duct is smaller than a passage area in the vicinity of the intake port of the duct, and a distance in further backward than the duct is smaller than the distance in the height direction in the vicinity of the middle of the duct, a passage area in further backward than the duct is smaller than the passage area in the vicinity of the middle of the duct.