A method of controlling braking of an all-wheel drive eco-friendly vehicle having a transfer case disposed between a driving motor and a plurality of driving wheels including a main driving wheel and an auxiliary driving wheel, the method comprising: determining a first required braking amount of the main driving wheel and a second required braking amount of the auxiliary driving wheel in a situation in which the vehicle needs to be decelerated while traveling; comparing the first required braking amount with a regenerative brake available amount of the driving motor; as a result of the comparing, when the first required braking amount is equal to or greater than the regenerative brake available amount, distributing (S830A) regeneration capability of the driving motor only to the main driving wheel through the transfer case, and when the first required braking amount is less than the regenerative brake available amount, distributing (S830B) the regeneration capability to both the main driving wheel and the auxiliary driving wheel through the transfer case; and executing each of a difference between the first required braking amount and first regeneration capability of the regeneration capability, distributed to the main driving wheel, and a difference between the second required braking amount and second regeneration capability of the regeneration capability, distributed to the auxiliary driving wheel, through a hydraulic brake device, wherein distributing the regeneration capability includes distributing the first regeneration capability and the second regeneration capability in a same distribution ratio as a distribution ratio of the first required braking amount and the second required braking amount. determining a first required braking amount of the main driving wheel and a second required braking amount of the auxiliary driving wheel in a situation in which the vehicle needs to be decelerated while traveling; comparing the first required braking amount with a regenerative brake available amount of the driving motor; as a result of the comparing, when the first required braking amount is equal to or greater than the regenerative brake available amount, distributing (S830A) regeneration capability of the driving motor only to the main driving wheel through the transfer case, and when the first required braking amount is less than the regenerative brake available amount, distributing (S830B) the regeneration capability to both the main driving wheel and the auxiliary driving wheel through the transfer case; and executing each of a difference between the first required braking amount and first regeneration capability of the regeneration capability, distributed to the main driving wheel, and a difference between the second required braking amount and second regeneration capability of the regeneration capability, distributed to the auxiliary driving wheel, through a hydraulic brake device, wherein distributing the regeneration capability includes distributing the first regeneration capability and the second regeneration capability in a same distribution ratio as a distribution ratio of the first required braking amount and the second required braking amount.