Provided are a parking assistance device for a vehicle and a parking control method thereof, capable of preventing collision with a stopper within a parking space by assisting parking in alignment with a parking reference line set with respect to an object located at a distance closest to the self vehicle among distances to objects located around a found parking space. The parking assistance device includes: a parking space searching unit configured to search for a parking space for parking of a self vehicle; a reception unit configured to receive sensing signals sensed from objects located around the parking space; a reference object determination unit configured to use the sensing signals to determine an object closest to the self vehicle as a reference object among the objects located around the parking space; and a parking reference line setting unit configured to set the parking reference line based on a front end of the determined reference object.