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The genus Nageia is an important group of Podocarpaceae,while the taxonomic position of Nageia has received varying treatments.Nageia was formerly treated as a section of genus Podocarpus.At present,the genus Nageia with seven living species is generally divided into Nageia sect.Nageia and Nageia sect.Dammaroideae (Mill 1999,2001) and mainly distributed in eastern Asia from northern latitude 30° to equator and coastal mountain areas and island areas of western Pacific Ocean (Sun et al.,2005).The earliest macrofossils of Nageia date back to Lower Cretaceous,occurring in Russian Far East,southwestern Japan and Henan,China.Later,a fossil leaf and fossil pollens of Nageia were respectively discovered from Eocene of Hainan Island and Upper Tertiary of Fujian,China.In this paper,a new species(including leaves and pollen cones),Nageia maomingensis sp.nov.,discovered from Maoming Basin,South China is described.This is by far the first using scanning electron microscope (SEM) to study fossil cuticles of Nageia.Its leaves are coriaceous,lanceolate-elliptical with entire margin,5.1-9.0 cm long and 1.4-1.9 cm wide,without midvein but with as many as 22 subparallel longitudinal veins.Pollen cones are cylindric,1.6 cm long and 0.4 cm wide.Epidermal cells are square or rectangular in shape,with straight or slightly undulating buttressed anticlinal walls.The new species is amphistomatic.Stomata are arranged in longitudinal rows continuously or discontinuously.Commonly,stomata are consisted of two guard cells and two to three subsidiary cells,with prominent polar extensions,stomatal plugs and Florin rings.Although both the present new species and Nageia hainanensis Jin et al.are amphistomatic,they have significant differences in veins,length-width ratio,stomatal density and epidermal cells between stomatal rows.The discovery of Nageia maomingensis sp.nov.further supports that Nageia could have originated in the northeastern part of Asia in the Early Cretaceous and spread to south China at least in the Eocene (Jin et al.2010),providing new fossil evidence for research on the paleoclimate and paleoenvironment of Maoming Basin.In this study,atmospheric CO2 during the Late Eocene is reconstructed and CO2 concentration is calculated by stomatal ratio method.The result suggests that the mean CO2 concentration was 569.5±81.2 ppmv during Late Eocene,indicating a CO2 concentration that was substantially higher than today.