The analysis of sulfur distributions in fluid catalytic cracking (FCC) naphtha and residue fluid catalytic cracking (RFCC) naphtha, produced by different refineries, reveals that the distribution of sulfur compounds in different naphtha are alike. The percentage of mercaptan sulfur and disulfide sulfur are low; the sulfide sulfur is in the middle and most part of sulfur in naphtha fraction is thiophenic sulfur, which is over 60% of the total sulfur. The only difference of sulfur distribution between FCC and RFCC naphtha is that the content of thiophenic sulfur in RFCC naphtha fraction is higher than that in FCC naphtha fraction, which almost accounts for 70% of the total sulfur. (C) 2002 Elsevier Science B.V. All rights reserved.