In　this　paper,　a　linear　multi-regression　model　was　used　to　study　the　degree　of　influence　of　various　operating　conditions　on　the　permeation　flux　of　deionized　water　and　bovine　serum　albumin　(BSA)　solutions　in　the　ranges　of　0.04-0.16　MPa　and　20-30　degrees　C　during　dead-end　microfiltration.　In　the　experiment,　two　kinds　of　membrane　were　used.　One　was　a　PVDF　membrane　with　pore　size　of　0.1　mu　m,　and　the　other　was　a　PTFE　membrane　with　a　pore　size　of　0.2　mu　m.　Experimental　and　analytical　results　showed　that　temperature,　pressure　and　concentration　had　a　significant　influence　on　the　microfiltration　membrane　flux.　For　deionized　water,　the　flux　increased　with　increasing　temperature　and　pressure,　and　the　relative　degree　of　influence　of　temperature　and　pressure　on　the　microfiltration　membrane　flu　K　was　different,　2%　and　98%,　respectively.　The　relationship　was　J(w)　=　-6.57　+　0.27　T+　133.27　P.　For　BSA　solutions,　the　flux　increased　with　increasing　temperature　and　pressure,　while　decreased　with　increasing　concentration.　The　degree　of　influence　of　pressure,　temperature　and　concentration　on　the　permeation　flux　was　69%,　18%,　13%,　respectively,　and　the　relationship　was　J　=　-1.28　+　0.22　T　+　33.11　P　-　1.04　C.　Therefore　the　relative　importance　of　pressure　on　the　membrane　flux　was　much　greater　than　that　of　temperature　or　concentration.