Premixed　catalytic　combustion　of　natural　gas　was　studied　over　the　honeycomb　monolith　wash-coated　with　palladium,　lanthanum,　strontium,　cobalt　and　manganese.　The　experimental　results　showed　that　the　temperature　of　the　flameless　catalytic　combustion　ranged　from　600°C　to　900°C.　Very　low　temperature　led　to　extinguishment　and　very　high　temperature　made　the　catalyst　disabled.　In　the　experiments,　the　natural　gas-air　ratios　ranged　from　6%　to　12%　volume　percentage　and　the　good　catalytic　effect　was　obtained　at　the　fuel-air　ratio　of　8%　when　the　noble　metal-palladium　reached　0.21%　based　on　the　weight　of　γ-Al2O3.　Meanwhile,　the　experiments　still　proved　in　the　shorter　monolith,　catalytic　combustion　was　in　very　good　condition　and　the　surface　temperature　of　monolith　was　relatively　lower.　Oppositely,　in　the　longer　monolith,　the　surface　temperatures　increased　and　the　lethal　NOx　emissions　were　slightly　increased.　Subsequently,　the　characteristics　of　heat　and　mass　transfer　in　catalytic　monolith　were　analyzed.