A　new　porous　plastic　optical　fiber　probe　was　synthesized　and　proposed　for　preparation　of　optical　chemical　sensor.　The　basic　principle,fabrication　and　characteristics　of　the　porous　plastic　optical　fiber　probe　are　described　in　detail.　The　polymer　fiber　was　made　from　the　stock　mixture　of　functional　monomer,cross-linking　reagent,pore-forming　reagent　and　indicator.　And　it　behaves　great　advantages　as　an　optical　fiber　probe.　This　new　porous　plastic　optical　fiber　probe　has　been　used　for　preparing　some　optical　chemical　sensors,　and　these　probes　have　been　used　for　determination　of　halides,　mercury,　ammonia,　oxygen　and　pH.