In　the　era　of　the　Internet　of　Things　(IoT),　it　is　a　promising　way　to　improve　system　energy　utility　and　better　meet　users＇　requirements　for　Quality　of　Service　(QoS)　via　integrating　nonorthogonal　multiple　access　(NOMA)　and　mobile-edge　computing　(MEC)　technologies.　In　light　of　this　idea,　we　investigate　device　access,　subchannel　division,　and　transmission　power　allocation　for　NOMA-enabled　IoT　systems.　To　maximize　the　energy　utility　of　IoT　systems　while　satisfying　the　minimum　demands　of　IoT　Devices　(IoTDs)　on　achievable　uplink　data　rate,　a　joint　optimization　problem　is　formulated　with　the　consideration　of　device　access,　subchannel　division,　and　transmission　power　allocation.　Due　to　the　nonconvexity　of　this　problem,　we　propose　an　alternating　optimization　algorithm　aiming　to　find　the　optimal　solution.　The　proposed　algorithm　first　decomposes　the　joint　optimization　problem　into　three　subproblems　through　the　block　coordinate　descent　(BCD),　and　then　obtains　the　near-optimal　solution　by　solving　the　decomposed　subproblems　alternately.　Extensive　simulations　validate　our　analysis　for　the　convergence　of　the　proposed　algorithm.　The　numerical　results　demonstrate　that　the　proposed　algorithm　significantly　outperforms　the　benchmark　algorithms　in　terms　of　improving　system　energy　utility.