台北凹陷柯柯亚构造八道湾组砂岩是在辫状河三角洲沉积环境下形成的一套富含火山物质的长石质岩屑砂岩和岩屑砂岩。根据常规薄片、铸体薄片和扫描电镜观察及x衍射资料分析．对八道湾组砂岩的岩石学特征、成岩作用阶段划分、成岩作用类型及其对孔隙的影响进行了研究。结果表明：研究区八道湾组砂岩现处于晚成岩A2期，经历的成岩作用有机械压实、绿泥石形成、石英次生加大、方解石析出、胶结作用及长石溶蚀作用。压实作用和胶结作用是主要的破坏性成岩作用，而溶蚀作用则是主要的建设性成岩作用，特别是长石的溶蚀是储层物性变好的重要成岩控制因素。

The sandstone of Badaowan Formation developed in Kekeya structure of Taibei Sag under braided delta is mainly composed offeldspathic lithie sandstone and lithic sandstone．By means of thin slices，cast section and scanning electron microscopy observation as well as X-ray diffraction analysis，the petrologic characteristics，diagenesis stage division，diagenesis type and the influence on pore of Badaowan Formation aye studied．The results show that the sandstone developed in study area is in late diagenesis A2 stage，and experienced compaction，chlorite formation，quartz secondary enlargement，calcite precipitation，cementation and feldspar denudation．Compaction and cementation aye the main destructive diagenesis，while denudation is the main constructive diagenesis．Especially，the feldspar denudation is the significant factors favorable for reservoir．