Abstract: A portable terminal auxiliary device having a portable terminal support function is provided. The portable terminal auxiliary device includes: a body part having a front surface and a rear surface; a front surface connector provided on the front surface of the body part and connected to a connector of a portable terminal side so as to exchange power and signals; a stand provided on the front surface of the body part so as to support a portable terminal together with the body part; and a rear surface connector electrically connected to the front connector and provided on the rear surface of the body part so as to be connected to a front connector of a second auxiliary device. Additional auxiliary device can be further connected to the portable terminal auxiliary device capable of supporting a portable terminal.