Abstract: The Laiyang Formtion shales in Laiyang sag,with oil and gas found,are well developed. Based on the field survey and lab analysis,the authors make a systematic study on the organic geochemical characteristics of the Laiyang Formtion shales in Laiyang sag. The source rocks of Laiyang Formation,with high total organic matters content ranging from 0. 22% to 3. 43%,mainly distribute in the Shuinan section and the Xiaoxiangzhuang section. Kerogen is composed of sapropelinite (40% -82%),vitrinite (3% -33%) and inertinite (10% -45%),and no exinite was found. Kerogen types include type Ⅱ₁,typeⅡ₂ and type Ⅲ,particularly type Ⅱ₁ and Ⅱ₂. The vitrinite reflectance ranges from 0. 50% to 2. 22%,it indicates that the shales have a high maturity of organic matter. Given the thickness of black shale,TOC,kerogen types,and vitrinite reflectance,Shuinan section of Laiyang formation is a favorable target for shale gas study in Laiyang sag.