A Smith and Crystal LCH microreactor was used in n-octane reforming. The useful catalyst volume of the reactor can be changed in the 4-15 cm(3) range. At the industrially used space velocity the conversion is close to 100%, therefore, the secondary reactions affect the product composition. In order to suppress these secondary reactions, the space velocity was varied between 1 h(-1) to 4 h(-1) The optimum space velocity in this microreactor was found to be at 4 h(-1). Among these conditions the conversion is appropriate for further investigations. The isomerization selectivity is increased while aromatization selectivity is decreased along with the space velocity increase.