The influence of the gasification temperature and S/B (mass ratio of steam to sludge) on the distribution characteristics of aromatic hydrocarbon compounds, nitrogen-containing compounds, oxygen-containing compounds and sulfur-containing compounds in sludge gasification tar was studied by GC-MS analysis. The results showed that the aromatic hydrocarbon compounds in the tar mainly were the phenanthrenes, naphthalenes, fluorenes and biphenyls compounds, and the highest yields of the phenanthrenes and naphthalenes always appeared at the gasification temperature of 850℃ when S/B values were 1.1, 1.5 and 1.9 respectively. The fluorenes yield firstly increased and then decreased with the gasification temperature increase when S/B values were 1.5 and 1.9 respectively, but the biphenyls yield firstly increased and then decreased with S/B value increase at 800℃, which its highest yield was 1.284 g/kg. Indoles compounds was the main chemical components in nitrogen-containing compounds, which its yield decrease with the gasification temperature increase when S/B values were 1.5 and 1.9 respectively. The main components in oxygen-containing compounds was phenols compounds, and its yield increased with S/B value increase when the gasification temperature was 750℃, which its highes tyield was 3.103g/kg. Besides, the main components of sulfur-containing compounds was 4,4'-bis (tetrahydrothiopyran), and naphtha[1, 2-b] thiophene with the yield of 0.263 g/kg only exist in the tar from the gasification at the temperature and S/B value of 850℃ and 1.9.