ABSTRACT: This study was carried out in Gölbaşı-Harmanlı (Adıyaman) region where coal basin exists. Chemical, petrographical and organic geochemical analyses of the Tertiary aged coals were taken in to consideration. Coal quality investigation along with proximate (moisture, volatile matter, fixed carbon, ash) and elemental analyses (C, H, O, S, N) were performed. The huminite reflectances of organically abundant matter and coal levels were found to be between 0.28% and 0.516% which refer to low maturity levels. This parameter is compatible with fluorescence colors, calorific value (average original 2736 - dry 3727 Kcal/kg) and average Tmax (422 oC). Organic matters of the investigated coals exhibit a low grade transformation, due to a low lithostatic pressure on them. In GC analyses, n-alkanes with low carbon numbers as n-C17, n-C27, n-C30 and n-C3 and CS2 as well as benzen were detected. Triterpanoid component was determined with GC-MS data and tends to imply high ground continental vegetation, but gammacera values to hypersaline depositional conditions. Gölbaşı coals show sub-bituminous and lignite coalification ranks. Rock Eval analysis results show TYPE II/III and III kerogen, with average Tmax value is 422 oC, and corresponding to the immature and premature rank for hydrocarbon generation. The coals are characterised with their abundance of huminite maceral group with small amount of inertinite and liptinite macerals. Mineral matters of the Gölbaşı coals are calcite, clays, and sulfur bearing minerals