In order to widen the application of sucrose thermal oligosaccharides caramel ( STOC) prepared by the thermolysis of acided sucrose,the pH value, characteristic absorption,browning degree,sugar content,antioxidant activity of the STOC prepared respectively by dry and wet processes at different temperatures were investigated and the main components as well as the thermal stability of the products were analyzed. The results show that,with the increase of temperature,the pH value of the STOC prepared by dry process first increases and then slowly decreases,but the one by wet process gradually decreases,that the characteristic absorption and browning of the STOC appear a up-trend in dry process and respectively reach the maximum of 3. 151 and 2. 128 at 160℃ in wet process,and that,for the STOC prepared by the two processes,the total sugar content gradually decreases,the reducing sugar content first increases and then decreases,and the antioxidant activity improves. Moreover,it is found that the STOC mainly contains oligosaccharides,such as sucrose and 1-kestose,together with small amount of glucose and fructose,etc.,and that the main compounds obtained from the STOC pyrolysis include furan,furan ketone,pyrazole,pyrrolidine,aldehyde,alkene and anhydride.