The thermal decomposition of carbonyl sulfide (sco) was studied in an integral reactor with various catalysts. An apparent activation energy of 28.7 Kcal/mole was measured for sco decomposition without a catalyst. In presence of a contact catalyst such as alumina or silica, the apparent activation energy was lowered to 5.6 Kcal/mole. At temperatures below 635 deg c, the main decomposition products of sco were co2 and cs2. At higher temperatures, the main products were CO and s. With pure chi-alumina, the decomposition of sco at 550 deg c was 35 percent, but when a stoichiometric quantity of so2 was added to sco, about 90 percent of the sco and so2 were converted at a much lower temperature (about 400 deg c). The degree of interaction of sco and so2 was greater with pure chi-alumina than when transition metals were present.