Improvement　of　catalysts　for　the　steam　reforming　of　tar　derived　from　the　pyrolysis　of　biomass　is　needed　in　terms　of　activity,　stability,　and　resistance　to　coke　deposition.　Ni　and　Co　are　known　to　be　active　components　for　the　steam　reforming　reaction,　and　one　effective　method　to　improve　the　catalytic　performance　is　the　alloying　of　the　active　metal　with　another　suitable　metal.　The　development　of　Ni-Fe,　Ni-Co,　and　Co-Fe　alloy　catalysts　is　described.　The　relationship　between　the　promoting　effect　of　alloy　formation　and　the　characterization　of　alloy　particles　is　introduced.　The　catalytic　performance　of　alloy　particles　is　greatly　influenced　by　the　properties　such　as　components,　compositions,　crystal　structures,　uniformity,　and　so　on.　In　particular,　utilization　of　hydrotalcite-like　compounds　as　the　catalyst　precursors　can　produce　alloy　particles　with　uniform　composition　as　well　as　higher　catalytic　activity　than　those　prepared　by　the　conventional　impregnation　method,　demonstrating　an　effective　method　for　preparing　excellent　alloy　catalysts.