In this study, we evaluated the properties of a reforming catalyst system for generating hydrogen from liquified petroleum gas (LPG) fuel and supplying hydrogen to an LPG engine. The fuel supply system of the LPG engine was modified in order to supply LPG to a reforming catalyst prior to combustion. A test apparatus was also built to evaluate the performance of a reforming catalyst system. Gas chromatography was used to measure H-2, N-2, O-2, CH4, and CO emissions, while CO2 emissions were measured using an exhaust gas analyzer. The products concentration of the reforming reactions according to reforming fuel quantity and air flow was analyzed. In actual engine operating conditions, H-2 yield and air flow were proportional, whereas H-2 yield and fuel reforming fuel quantity were inversely proportional. The experimental results of the reforming reaction under various conditions will be used as the basic data for integrating the reforming catalyst system into an actual operating engine. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.