A method for giving a warning on a blind spot of a vehicle based on vehicle to vehicle communication, comprising steps of: (a) if a rear video of a first vehicle is acquired from a rear camera monitoring a rear area of the first vehicle, a first blind-spot warning device of the first vehicle performing a process of transmitting the rear video of the first vehicle to a blind-spot monitor, to thereby allow the blind-spot monitor to determine whether one or more nearby vehicles are shown in the rear video of the first vehicle by analyzing the rear video of the first vehicle based on a convolutional neural network, and thus to output first blind-spot monitoring information which is a result of determining whether at least one of the nearby vehicles shown in the rear video of the first vehicle is located in a first blind spot of the first vehicle; and (b) if second blind-spot monitoring information, which is a result of determining whether a second vehicle is located in the first blind spot of the first vehicle, is acquired from a second blind-spot warning device of the second vehicle located in the rear area of the first vehicle, over the vehicle to vehicle communication, the first blind-spot warning device performing a process of giving a warning that at least one of the second vehicle and the nearby vehicles is located in the first blind spot by referring to the first blind-spot monitoring information and the second blind-spot monitoring information, characterized in that, at the step of (b), the first blind-spot warning device performs a process of acquiring GPS location information on the second vehicle from the second blind-spot warning device over the vehicle to vehicle communication, wherein, if a GPS confidence value of the GPS location information on the second vehicle transmitted from the second vehicle is determined as valid, the first blind-spot warning device performs a process of giving a warning that the second vehicle is located in the first blind spot through determining whether the second vehicle is located in the first blind spot by referring to the GPS location information on the second vehicle, and wherein, if the GPS confidence value of the GPS location information on the second vehicle transmitted from the second vehicle is determined as not valid, the first blind-spot warning device performs a process of giving a warning that at least one of the second vehicle and the nearby vehicles is located in the first blind spot by referring to the first blind-spot monitoring information and the second blind-spot monitoring information. (a) if a rear video of a first vehicle is acquired from a rear camera monitoring a rear area of the first vehicle, a first blind-spot warning device of the first vehicle performing a process of transmitting the rear video of the first vehicle to a blind-spot monitor, to thereby allow the blind-spot monitor to determine whether one or more nearby vehicles are shown in the rear video of the first vehicle by analyzing the rear video of the first vehicle based on a convolutional neural network, and thus to output first blind-spot monitoring information which is a result of determining whether at least one of the nearby vehicles shown in the rear video of the first vehicle is located in a first blind spot of the first vehicle; and (b) if second blind-spot monitoring information, which is a result of determining whether a second vehicle is located in the first blind spot of the first vehicle, is acquired from a second blind-spot warning device of the second vehicle located in the rear area of the first vehicle, over the vehicle to vehicle communication, the first blind-spot warning device performing a process of giving a warning that at least one of the second vehicle and the nearby vehicles is located in the first blind spot by referring to the first blind-spot monitoring information and the second blind-spot monitoring information, characterized in that, at the step of (b), the first blind-spot warning device performs a process of acquiring GPS location information on the second vehicle from the second blind-spot warning device over the vehicle to vehicle communication, wherein, if a GPS confidence value of the GPS location information on the second vehicle transmitted from the second vehicle is determined as valid, the first blind-spot warning device performs a process of giving a warning that the second vehicle is located in the first blind spot through determining whether the second vehicle is located in the first blind spot by referring to the GPS location information on the second vehicle, and wherein, if the GPS confidence value of the GPS location information on the second vehicle transmitted from the second vehicle is determined as not valid, the first blind-spot warning device performs a process of giving a warning that at least one of the second vehicle and the nearby vehicles is located in the first blind spot by referring to the first blind-spot monitoring information and the second blind-spot monitoring information.