In　order　to　examine　the　law　of　the　gas-liquid　two-phase　flow　at　various　inlet　positions　of　a　bubble　column,　an　Euler-Euler　two-fluid　model　coupled　with　the　population　balance　model　(PBM)　was　used　to　simulate　the　effects　of　four　inlets　at　various　positions　in　the　middle　of　the　bubble　column　bottom　on　gas-liquid　two-phase　flow　in　the　bubble　column.　We　verified　the　mesh　of　the　computational　domain　and　gas　hold-up　distribution　by　comparing　with　experimental　data.　This　study　also　investigated　dynamic　behaviours　of　gas　hold-up,　bubble　number　density,　liquid　horizontal　velocity,　etc.,　which　provide　instructions　and　basis　for　the　design　of　the　bubble　column.　The　simulated　results　using　an　Euler-Euler　two-fluid　model　with　PBM　were　found　to　be　consistent　with　the　experimental　results　and　better　than　those　calculated　using　an　Euler-Euler　two-fluid　model　with　single　bubble　diameter.　Furthermore,　the　dynamic　behaviours　of　gas　hold-up,　liquid　horizontal　velocity,　distribution　of　gas　hold-up,　and　vortex　strength　were　all　affected　by　the　inlet　position.　When　the　inlet　was　farther　from　the　middle　of　the　bottom　of　the　bubble　column,　the　gas　hold-up　had　an　S-shaped　distribution　and　the　vortex　strength　increased;　the　gas　hold-up　and　bubble　plume　oscillation　period　initially　increased　and　then　decreased.　The　bubble　number　density　was　not　significantly　affected　by　the　inlet　positions　in　the　bubble　column.　Moreover,　the　group　with　the　bubble　diameters　of　5.95　mm　had　the　largest　bubble　number　density.　©　2018,　Editorial　Department　of　Journal　of　Southwest　Jiaotong　University.　All　right　reserved.