Abstract: Zang 1 Well is the well where the first commercial oil and gas discovery in Lupola basin was located.Geochemical study shows that its crude oil is essentially conventional oil characteristic of high wax and low sulfur;chemically it is classified as intermediate aromatics;and its source materials include alga and higher plants,ranging from sapropelic to humic-sapropelic types;its orlginal depositional environment is salt lake basin- Basically the evolution of crude oil reaches to low-mature stages;and waterwashing and oxidation with a relative weak biodegradation are considered as the main epigeneses.