To provide an air blowing part structure for a vehicle, capable of avoiding a shortage of the amount of air to be blown into a cabin through a ventilation duct and the wind leak noise, and capable of reducing the die cost and the management expenses of the ventilation duct.

In a specification including a defroster duct, an engagement projection part projected in an end of the defroster duct on an upstream side thereof is engaged with an engagement hole formed in an end of a ventilation duct 10 on an upstream side thereof, and the ventilation duct 10 with a specification including the defroster duct and the ventilation duct 10 with a specification not including a defroster duct are standardized in parts. The ventilation duct 10 with any specification is formed with an engagement hole in an end on an upstream side thereof. A ventilation duct displacement preventing wall 8 is provided in a ventilation duct connecting part 6 of an air conditioner 1 with the specification not including a defroster duct, so that the ventilation duct displacement preventing wall 8 closes the engagement hole in the specification not including a defroster duct.