Gate　dielectric/substrate　interface　is　crucial　to　the　electrical　performance　of　nano-devices.　However,　the　investigation　on　characterization　of　interfacial　atomic　and　electronic　structures　is　still　lacking.　In　this　paper,　first　principles　modeling　and　calculation　were　performed　to　investigate　the　atomic　and　electronic　properties　of　the　HfO2/Si　interface.　The　optimized　bulk　models　of　Si　and　tetragonal　HfO2　were　combined　to　build　the　HfO2/Si　interface　with　the　assistance　of　Quantum　Espresso　software.　Band　structure　and　density　of　states　were　calculated　based　on　the　density　functional　theory　(DFT).　It　was　found　that　the　weakly　bounded　oxygen　moves　towards　the　interfacial　region　obviously　after　relaxation　which　due　to　the　strong　interaction　between　interfacial　Si　and　oxygen　atoms.　Chemical　bonds　at　the　HfO2/Si　interface　are　easier　to　be　broken　than　that　of　bulk　atoms　because　interfacial　bond　length　increases　significantly.　The　additional　interfacial　states　were　generated　after　the　construction　of　the　interface.　Our　results　reveal　the　mechanism　of　the　changes　between　bulk　models　and　the　HfO2/Si　interface　from　an　atomic　perspective,　which　is　expected　to　be　benefited　to　the　performance　optimization　of　electronic　devices.　©　2021,　Beijing　Oriental　Sun　Cult.　Comm.　CO　Ltd.