A server and a method for automatically controlling regenerative braking of an eco-friendly vehicle are provided. A regenerative braking level is calculated by considering driving information and a driving environment of a vehicle using a regenerative braking controlling server. The calculated regenerative braking level is transmitted to a regenerative braking controlling apparatus mounted within the vehicle and thus, even though a vehicle driver does not directly set the regenerative braking level, the regenerative braking level transmitted from the regenerative braking controlling server is received through the regenerative braking controlling apparatus of the vehicle to perform regenerative braking, thereby enhancing driving convenience and stability, and fuel efficiency.