Early　failure　of　the　coal　gasifier　burner　used　in　integrated　gasification　combined　cycle　plants　poses　serious　technical　and　safety　issues.　The　aim　of　this　study　was　to　determine　the　causes　of　a　failed　burner　based　on　chemical　composition　of　material　and　characteristics　of　corrosion　products　and　cracks.　Furthermore,　microstructures　of　the　failed　component　at　different　depths　were　compared　to　investigate　the　phase　degradation.　The　study　found　that　sulfurization　and　chlorination　were　the　main　causes　for　the　failure　of　current　coal　gasifier　burner.　Sulfidation　contributed　to　the　crack　propagation,　while　chlorine　concentrated　in　the　corrosion　layer　produced　significant　cracks　and　spallations.　The　overheating　was　supposed　to　be　responsible　for　the　non-uniform　distribution　of　precipitations　in　the　failed　burner　from　fire　side　to　water　side.