A secondary battery pack comprising: a battery cell having an electrode assembly of a cathode/separator/anode structure mounted in a battery case together with an electrolyte in a sealed state, the battery cell being provided at the top thereof with a pair of coupling grooves, into which connection coupling members are inserted, each of the coupling grooves having a predetermined depth; an insulative mounting member having openings, through which electrode terminals of the battery cell are exposed to the outside, the insulative mounting member being configured to have a structure in which a protection circuit module is disposed at the top of the insulative mounting member, the insulative mounting member being mounted to the top of the battery cell; a protection circuit module having a protection circuit to control overcharge, overdischarge and overcurrent of the battery cell, the PCM being provided with a pair of connection coupling members for mechanical coupling and electrical connection with the battery cell, the connection coupling members protruding downward, the PCM being disposed on the insulative mounting member; an insulative cap coupled to the top of the battery cell so that the insulative cap surrounds the insulative mounting member in a state in which the PCM is disposed on the insulative mounting member, wherein the connection coupling members are inserted into the coupling grooves formed at the electrode terminals of the battery cell through the openings of the insulative mounting member in a state in which the insulative mounting member is mounted to the top of the battery cell, thereby achieving the coupling of the PCM to the battery cell and the insulative mounting member and the electrical connection between the battery cell and the PCM, wherein the top of the insulative mounting member is formed in a shape corresponding to the PCM so that the PCM is mounted on the top of the insulative mounting member and fixed to top of the insulative mounting member in position, and the insulative mounting member is provided at opposite outermost protruding ends thereof with protruding parts configured to be coupled to the insulative cap, and wherein the PCM is provided at opposite ends thereof with grooves depressed inward so as to have a predetermined width, and the insulative mounting member is provided at the tops of the protruding parts thereof with coupling protrusions protruding inward so as to correspond to grooves. a battery cell having an electrode assembly of a cathode/separator/anode structure mounted in a battery case together with an electrolyte in a sealed state, the battery cell being provided at the top thereof with a pair of coupling grooves, into which connection coupling members are inserted, each of the coupling grooves having a predetermined depth; an insulative mounting member having openings, through which electrode terminals of the battery cell are exposed to the outside, the insulative mounting member being configured to have a structure in which a protection circuit module is disposed at the top of the insulative mounting member, the insulative mounting member being mounted to the top of the battery cell; a protection circuit module having a protection circuit to control overcharge, overdischarge and overcurrent of the battery cell, the PCM being provided with a pair of connection coupling members for mechanical coupling and electrical connection with the battery cell, the connection coupling members protruding downward, the PCM being disposed on the insulative mounting member; an insulative cap coupled to the top of the battery cell so that the insulative cap surrounds the insulative mounting member in a state in which the PCM is disposed on the insulative mounting member, wherein the connection coupling members are inserted into the coupling grooves formed at the electrode terminals of the battery cell through the openings of the insulative mounting member in a state in which the insulative mounting member is mounted to the top of the battery cell, thereby achieving the coupling of the PCM to the battery cell and the insulative mounting member and the electrical connection between the battery cell and the PCM, wherein the top of the insulative mounting member is formed in a shape corresponding to the PCM so that the PCM is mounted on the top of the insulative mounting member and fixed to top of the insulative mounting member in position, and the insulative mounting member is provided at opposite outermost protruding ends thereof with protruding parts configured to be coupled to the insulative cap, and wherein the PCM is provided at opposite ends thereof with grooves depressed inward so as to have a predetermined width, and the insulative mounting member is provided at the tops of the protruding parts thereof with coupling protrusions protruding inward so as to correspond to grooves.