The influence of the method for loading platinum precursor and adding KCl, KCl loading content, calcination temperature, KCl addition procedure, various additives, and water washing on the activity and selectivity of Pt/KL catalysts for hexane reforming reaction has been investigated. The catalyst preparation methods involve ion exchange (IE), incipient wetness impregnation (IWI), and coimpregnation with KCl (IWI-KCl). The Pt/KL catalysts PrePared by ion "Change with [Pt(NH3)4]Cl2 followed by impregnation with KCl (EE-KCl) gave much higher activity and selectivity for benzene formation than the catalysts prepared by coimpregnation of KL zeolite with [Pt(NH3)4]Cl2 and KCl. The IE-KCl catalyst with KCl/Pt molar ratio of 4.5 showed 100.0% conversion of hexane and 89.3% yield of benzene at 743 K and 0.2 MPa. The IE-KCl catalysts exhibited lower H/Pt ratios than the IE catalyst. The KCl addition procedures markedly affected the activity and selectivity of the Pt/KL catalyst; the addition of KCl to the IE sample prior to calcination and reduction was necessary for the catalyst to exhibit the high activity in benzene formation. It has also been found that the performance of Pt/KL catalysts is markedly affected by the calcination temperature. With the IE-KCl catalysts, however, the decrease in the benzene yield caused by high-temperature calcination was not as serious as with the IE catalyst. In contrast, with the IWI and IWI-KCl catalysts, the activity for benzene production was highly sensitive to the calcination at high temperature, drastically decreasing by calcination at 823 K. The Cl species on the IE-KCl catalysts may have existed in the state of KCl.