This　paper　investigated　the　influence　from　apparent　density　on　rheological　property　of　lightweight　and　heavyweight　concrete.　The　apparent　densities　of　1761　kg/m3,　3048　kg/m3　and　3548　kg/m3　were　selected.　The　obtained　results　showed　when　the　slump　for　lightweight　and　heavyweight　concrete　was　controlled　in　the　range　of　160　+/-　10　mm,　the　yield　stress　(z0)　and　plastic　viscosity　(pp)　increased　significantly　as　the　addition　of　the　apparent　density.　The　slump　tests　of　fresh　lightweight　and　heavyweight　concrete　were　numerically　simulated　with　an　error　of　less　than　3.0　%　using　lattice　Boltzmann　method　(LBM).　The　established　slump　model　could　accurately　predict　the　flow　behavior　and　characteristics　of　lightweight　and　heavyweight　concrete　at　different　apparent　densities.　By　comparing　the　distribution　of　physical　fields　such　as　velocity　and　pressure,　the　effect　of　apparent　density　upon　the　flow　behavior　of　lightweight/heavyweight　concrete　was　analyzed　in　depth,　and　the　changing　rule　in　rheological　performance　of　concrete　with　different　apparent　densities　was　clarified.