Catalytic performance of phosphate-modified carbon nanotube(PoCNT) catalysts for oxidative dehydrogenation(ODH) of n-butane has been systematically investigated. The Po CNT catalysts are characterized by SEM, TEM, XPS and TG techniques. We set the products selectivity as a function of butane conversion over various phosphate loading, and it is found that the PoCNT catalyst with the 0.8% phosphate weight loading(0.8PoCNT) exhibits the best catalytic performance. When the phosphate loading is higher than 0.8 wt%, the difference of catalytic activity among the PoCNT catalysts is neglectable. Consequently, the ODH of n-butane over the 0.8PoCNT catalyst is particularly discussed via changing the reaction conditions including reaction temperatures, residence time and n-butane/O_2 ratios. The interacting mechanism of phosphate with the oxygen functional groups on the CNT surface is also proposed. Catalytic performance of phosphate-modified carbon nanotube (PoCNT) catalysts for oxidative dehydrogenation (ODH) of n-butane has been systematically investigated. The Po CNT catalysts are characterized by SEM, TEM, XPS and TG techniques. function of butane conversion over various phosphate loading, and it is found that the the PoCNT catalyst with the 0.8% phosphate weight loading (0.8PoCNT) exhibits the best catalytic performance. When the phosphate loading is higher than 0.8 wt%, the difference of catalytic activity among the ODH of n-butane over the 0.8PoCNT catalyst is specifically discussed via changing the reaction conditions including reaction temperatures, residence time and n-butane / O_2 ratios. The interacting mechanism of phosphate with the oxygen functional groups on the CNT surface is also proposed.