The organic geochemical characteristics of hydrogen-rich coal in southern China were investigated synthetically through organic geochemistry and carbon isotope analyses.The results showed that the hydrogen contents of the test samples were more than 5.0％ and the H/C atomic ratios were between 0.76-1.06.Samples were found to be composed mostly of Type Ⅱ-Ⅲ kerogen,consistent with good hydrocarbon-generation potential.The Ro (0.54-1.10％) and Tmax (430-453℃) values imply that the hydrogen-rich coals were in low maturity to mature stages.Stable carbon isotopic ratios(δ13Corg) of the samples used varied from-24.5‰ to-23.4‰,the barkinite content ranging from 13.9％ to 83.3％,indicating a predominantly terrestrial origin with marine influence during coal formation.Some organic geochemical parameters showed corresponding changes as the hydrogen content increased from 5.0％ to 7.0％,however,the source inputs changed significantly when hydrogen content was greater than 6.0％.Terrestrial higher plants gradually become predominant within the coal-forming materials,whereas this dominant position is not apparent at lower hydrogen contents,which is attributable to the strong seawater effect during the hydrogen-rich coal formation process.