Abstract: Phenanthrene and methyphenanthrenes, further separated and enriched from aromatic hydrocarbon fraction with adding the polarity of eluant step by step, can meet the requirernent of individua] carbon isotope analysis. The carbon isotopic cormpositions of alkylnaphthalenes and alkylphenanthrenes in the crude oils of Turpan-Hami basin are detennined by using the above method of enrichment and gas chrormatogra-phy-isotope ratio mass spectrometry (CC-IRMS) technique. The result shows that the alkylnaphthalenes and alkylphenanthrenes frorn coal measures obviously enriched in PC, ranging from-20%o~-28%o, comared with tbe same compounds from marine source, and the 83C value of individual polycyclie aromatic hydrocarbons can be considered as a potential marker for the origin of organic matter and oil correlation.

Key words: Turpan-Harni basin, alkylnaphthalenes, alkylphenanthrenes, caxbon isotope