Abstract: Based on cautiously filtrating biomarker parameters of oil and source rock, by using mathematics method---cluster analysis, relationship between oil and source rock can be established shortcuttedly from many samples. This not only predigests the process of hydrocarbon source correlation, but also enhances the accuracy of hydrocarbon source correlation. This method is successfully applied in Mid-South region of Liaodong Bay in Bohai Area from two aspects: hydrocarbon source correlation of single well and hydrocarbon source correlation of area. Following are conclusions by further analysis: oil ofWell LD6-2-1 comes from source rocks of the lower part of the Third Member of Shahejie Formation of Liaozhong Sag; oil of Well LD12- 1-1D, which was thought that source rock of the Third Member of Shahejie Formation was its source, comes from source rock of the First and Second Members of Shahejie Formation. Oil in areas from JX1-1 to LD12-1 is classified into three types: the first type comes from source rocks of Lower or Middle Submember of the Third Member of Shahejie Formation in Liaozhong Sag, which is characterized by C29 stigmastane predominance, higher index of maturity (C29 αα S/C29(αα R+ αα S)), higher content of arranged cholestane, lower content of gammacerane and ergostane; the second type comes from source rocks of Lower Submember of the Third Member of Shahejie Formation, which is characterized of C27 cholestane predominance, higher index of maturity, higher content of arranged cholestane, lower content of gammacerane and ergostane; the third type comes from source rocks of the First and Second Members of Shahejie Formation, which is characterized of C27 cholestane predominance, lower index of maturity and content of arranged cholestane, higher content of gammacerane and ergostane.

Key words: Liaodong Bay, hydrocarbon source correlation, cluster analysis, biomarker