An　adjustable　parameter　k　was　introduced　in　an　original　model　based　on　Darcy＇s　Law　to　increase　its　accuracy,　and　a　new　semi-empirical　model　predicting　permeate　flux　for　dead-end　microfiltration　(MF)　systems　was　proposed.　The　adjustable　parameter　k　was　validated　in　laboratory　experiments　by　using　two　different　suspensions　(kaolin　and　yeast).　The　membranes　adopted　in　this　research　included　flat　PES　and　PVDF　with　0.2　mu　and　0.1　mu　average　pore　size　respectively.　The　experiments　showed　that　this　adjustable　parameter　was　almost　independent　of　operating　conditions　pressure,　concentration　and　temperature),　but　depended　on　the　character　of　the　cake　formed　on　the　membrane　surface　and　on　the　type　of　membrane.　The　average　values　of　k　for　yeast　and　kaolin　are　4.15　and　1.10　respectively.　The　results　showed　good　agreement　between　model　prediction　and　experimental　observations.