通过对江苏下扬子地区笔石反射率的研究，发现随埋深增加笔石反射率增高，并建立了笔石反射率与牙形刺色变指标的对应关系，又以牙形刺色变指标与镜质体反射率之间的对应关系为“桥梁”，进一步建立了笔石反射率与镜质体反射率的对应关系，从而为下古生界烃源岩有机质成熟度的评价提供一项新的可靠的评价指标。 Based on the study of the penolith reflectivity in the Lower Yangtze region of Jiangsu Province, it is found that the reflectivity increases with the burial depth, and the corresponding relationship between the penolith reflectivity and the conodont color index has been established. And the relationship between vitrinite reflectance as a “bridge” to further establish the pen-stone reflectance and vitrinite reflectance of the corresponding relationship, so as to evaluate the maturity of organic matter in the Lower Paleozoic source rocks New and reliable evaluation index.