The defects at the 3C-SiC/SiO2 interface have been studied by X-band EPR spectroscopy in oxidized porous 3C-SiC. One interface defect is detected; its spin Hamiltonian parameters, spin S=1/2, C-3V symmetry, g(//)=2.00238 and g⊥=2.00317, central hyperfine interaction (CHF) with one carbon atom and A(B//)[(001])=48G and superhyperfine (SHF) interaction with three equivalent Si neighbouf atoms and T-B//[001]=12.4G, allow us to attribute the center to a sp(3) coordinated carbon dangling bond center, P-bC.