With the increasing construction of high-rise and long-span buildings, composite structure systems have been increasingly studied in various fields. This study presents and evaluates a new concept hybrid composite beam, using monotonic and cyclic tests. 6 bending specimens and 2 beam-to-column connection specimens of the new concept hybrid composite beam were fabricated for bending and seismic performance testing. The bending behavior test results showed that the capacity of the beam stably increased in proportion to the depth of beams and the thickness of steel plates. Also, sufficient maximum moment was secured compared to nominal moment. The seismic performance test results showed that the maximum moment was above the plastic moment, and the connection was intermediate moment frame.