Petrography and petrology of arenite sandstone at Ban Huai Krathathong area. Study area is located in the south of Sai yok district and covering approximately 26 square kilometer. This study is aimed to classified type of their sandstone, to interpret for tectonic setting, and to describe the sandstone diagenesis of this area. The method are field investigation for sample rock and petrography investigation concentrates on the detrital description of composition and textural relationship of the rock by thin section and staining mineral for modal analysis in polarizing microscope. The studies indicate that………