Mesoporous　55　wt.%　Ni/MgO　and　group　VIB　metal　(Cr,　Mo　or　W)-doped　catalysts　were　prepared　using　the　facile　＂one-pot＂　evaporation-induced　self-assembly　in　ethanol　and　wetness　impregnation　methods,　respectively.　Physicochemical　properties　of　the　as-prepared　catalysts　were　characterized　by　means　of　the　BET,　XRD,　SEM,　TEM,　HAADF,　XPS,　H-2-TPR,　TPO,　and　Raman　techniques.　The　doping　of　Cr　to　55　wt%　Ni/MgO　improved　catalytic　activity　and　stability　for　the　decomposition　of　methane　under　harsh　reaction　conditions.　The　maximal　initial　methane　conversions　of　80,　87,　and　75%　were　achieved　over　the　55　wt.%　Ni-xCr/MgO　(denoted　as　55Ni-xCr/MgO;　x　=　5,　10,　and　15　wt.%)　at　675　degrees　C　and　GHSV　=　48,000　mL/(g　h),　respectively.　It　is　concluded　that　the　high　catalytic　efficiency　of　the　Cr-doped　sample　in　methane　decomposition　was　associated　with　its　high　surface　area,　high　oxygen　adspecies　concentration,　and　good　low-temperature　reducibility.　In　addition,　multi-walled　carbon　filaments　with　metal-encapsulated　carbon　particles　were　deposited　on　the　Cr-doped　catalysts,　and　the　ordered　carbon　filaments　with　different　diameters　and　good　crystallinity　were　produced　on　the　surface　of　the　55Ni-10Cr/MgO　catalyst.