Abstract: Kinetics of the steam reformig of n-butane,n-hexane,n-heptane,n-nonane and i-octane on Z409 catalystwere studied at atmospheric pressure by using an internal recycle gradientless reactor.The reaction temperaturewas varied in the range of 743-853K,the steam carbon molar ratio 3-5.The experimental results showed thatthe reforming products contained no hydrocarbon other than methane.In addition,the product distributionof different n-paraffins were similar,but the product distribution of i-octane was different from that of n-paraffins.A reaction scheme for the steam reforming of paraffin has been proposed and the hyperbolic type rateequations were derived.It is clear that the obtained kinetic model could simulate the experimental results ofi-octane as well as different n-paraffins satisfactorily.