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讨论了风化作用对西宁盆地野外露头烃源岩有机质性质的影响及校正方法。风化作用可使有机质丰度降低，风化因子为２．０７～４．４６。现今中侏罗统野外露头泥岩的有机质丰度为中等，经风化校正之后，达到了好烃源岩的标准。风化作用对有机质类型参数影响强度从弱到强的顺序为Ｈ／Ｃ原子比、αααＣ２７甾烷质量分数、干酪根碳同位素组成、红外光谱１４６０ｃｍ－１与１６００ｃｍ－１处的峰高比、干酪根显微组分质量分数、ＩＨ、Ｏ／Ｃ原子比。在研究野外露头的有机质类型时，应选取那些受风化作用影响较小的参数，作为主要指标。同时，也要参考当时的沉积环境，因为古代的沉积环境决定了现在的有机质类型。通过人工改变埋藏轨迹和地热史的研究，我们预测西宁盆地内中侏罗统烃源岩的Ｒｏ为０．８４％，已进入大量生油的成熟阶段，而中侏罗统野外露头的实测Ｒｏ为０．５９％，属于低成熟阶段，这一研究对西宁盆地的含油气远景评价无疑具有重要意义
The effect of weathering on the organic matter properties of outcrops in Xining basin and the correction methods are discussed. Weathering can reduce the abundance of organic matter, weathering factor of 2.07 ~ 4.46. Nowadays, the abundance of organic matter in the mudstone of the Middle Jurassic outcrops is moderate, and after the weathering correction, it has reached the standard of good source rocks. The intensity of weathered organic matter from weak to strong order was H / C atomic ratio, αααC27 sterane mass fraction, kerogen carbon isotope composition, peak height ratio at 1460cm-1 and 1600cm-1 of infrared spectrum, Kerogen microstructure mass fraction, IH, O / C atomic ratio When studying the types of organic matter in the outcrops of the field, the parameters that are less affected by weathering should be selected as the main indicators. At the same time, we should refer to the sedimentary environment of the time, because the ancient sedimentary environment determines the current organic matter type. By artificially changing the burial trajectory and geothermal history, we predict that the Ro of the Middle Jurassic source rocks in Xining Basin is 0.84% and has entered the mature stage of abundant oil production. However, the Ro Is 0.59%, belonging to the low maturity stage. This research is of great significance to the evaluation of the hydrocarbon-bearing future in the Xining basin