The influence of yttrium and ytterbium on the catalyticperformance of Pt-Re reforming cata-lysts was studied in a continuous flow pressurized microreactor-chromatograph system and pilot unit. Theresults of micro-reactor test showed that both yttrium and ytterbium could improve the selectivity of Pt-Recatalysts for the conversion ofn-heptane as well as MCP into aromatics, but also suppressed their activityas well. Pilot test results showed that yttrium and ytterbium enhanced both the selectivity and activity ofPt-Re catalysts for naphtha reforming. Yttrium showed more improvement than ytterbium. The perfor-mance difference between microreactor test and pilot test might be due to the difference in improvement ofcatalytic stability of yttrium or ytterbium modified Pt-Re catalysts. Yttrium and ytterbium improved thecoking resistance of yttrium or ytterbium modified Pt-Re catalysts. TEM determination results indicatedthat both yttrium and ytterbium had improved the thermal stability of Pt-Re catalysts.