A　model　of　inhomogeneous　three-dimensional　Navier-Stokes　equations　was　studied　in　this　paper.　By　using　the　energy　method,　Littlewood-Paley　paraproduct　decomposition　techniques　and　Sobolev　embedding　theorem　study　of　the　global　regularity　of　solutions　were　adopted.　The　dissipative　term　Δu　in　the　classical　inhomogeneous　Navier-Stokes　equations　is　replaced　by　-D2u　and　a　new　Navier-Stokes　equations　model　was　obtained,　where　D　was　a　Fourier　multiplier　whose　symbol　is　m(ξ)=|ξ|5/4.　Blow-up　criterion　and　global　regularity　of　this　model　were　proved　for　the　initial　data　(ρ0,　u0)∈H3/2+ε×Hδ,　where　ε　and　δ　are　arbitrary　small　positive　constants.　©　2017,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.