Abstract: 22 crude oils of the Tahe Oil Field have been quantitatively analyzed with gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) for saturate and aromatic biomarkers. The contents of dibenzothiophene (DBT) and pristane (Pr) of middle-south and east area oils are relatively higher than those of middle-north area, which indicates that the former has a depositional environment of carbonite and stronger reducing environment than the latter. The content of C₃₅ homohopanes is higher in the oils of middle-north area than those of south-east, indicating for delamination water body of the former and stronger reducing environment. The content of C₂₉S steranes increases with that of DBT and methyl phenanthrenes and maturity degree. The high contents of 25-norhophane and bisnorhopane in middle-north area reveal the experience of biodegradation.