Accumulating　evidences　suggest　that　large-scale　loss　of　5-hydroxymethylcytosine　(5-hmC)　is　an　epigenetic　hallmark　in　different　cancers.　However,　the　levels　of　5-hmC　in　laryngeal　squamous　cell　carcinoma　(LSCC)　and　its　prognostic　value　in　this　cancer　remain　largely　unknown.　Using　dot-blot　and　quantitative　RT-PCR　assays,　we　investigate　5-hmC　levels　and　expression　of　TET-1,　-2　and　-3　in　LSCCs　and　explore　the　association　of　5-hmC　levels　with　clinicopathological　characteristics　and　clinical　outcome　of　LSCC　patients.　Our　data　showed　that　5-hmC　was　significantly　decreased　in　LSCCs　as　compared　with　matched　normal　tissues.　We　also　found　a　strong　link　between　decreased　5-hmC　and　the　reduction　of　TET-1　gene　expression,　but　not　TET-2　or　-3,　suggesting　that　decreased　TET-1　expression　was　implicated　in　5-hmC　loss　in　LSCC.　Moreover,　Mann-Whitney　U　tests　showed　that　5-hmC　content　was　significantly　associated　with　smoking　(P　=　0.039)　and　tumor　invasion　(P　=　0.004).　Importantly,　we　found　that　decreased　5-hmC　was　significantly　associated　with　poor　survival　of　early-stage　LSCC　patients　(P　=　0.043).　Altogether,　our　findings　implicate　that　decreased　5-hmC　probaly　caused　by　the　reduction　of　TET-1　is　crucial　to　the　clinical　pathology　of　LSCC　and　is　a　poor　prognostic　factor　in　ealry-stage　LSCC　patients.