The　existence　of　decoherence-free　subspace　(DFS)　has　been　discussed　widely.　In　this　paper,　we　propose　an　alternative　scheme　for　generating　the　four-atom　W　states　by　manipulating　DF　qubits.　The　atoms　are　divided　into　two　pairs　and　trapped　in　two　separate　optical　cavities.　Manipulation　of　atoms　within　DFS　may　generate　a　two-atom　maximally　entangled　state　in　an　individual　cavity,　which　is　a　stable　state.　After　driving　the　system　out　of　DFS,　the　atoms　will　interact　resonantly　with　the　cavity　field.　The　photons　leaking　from　the　cavities　interfere　at　the　beamsplitter,　which　destroys　which-path　information,　and　are　finally　detected　by　one　of　the　detectors,　leading　to　the　generation　of　a　W　state.　In　addition,　the　numerical　simulation　indicates　that　the　fidelity　of　the　prepared　state　can,　for　a　very　wide　parameter　regime,　be　very　close　to　unity.　©　2008　Chin.　Phys.　Soc.　and　IOP　Publishing　Ltd.