Chloroplast DNA (cpDNA) atpB-rbcL intergenii spacers o\ individuals of Alsophila podophylla, collected from eight relict populations distributed in Hainan and Guangdong Province, southern China, were sequenced. Sequence sizes were 726 or 727bp. Base composition had a high A+T content of 62.67-63.00%. Sequences were assessed as evolutionarily neutral 0.76638, P > 0.10). Eight haplotypes were identified based on a statistical parsimony algorithm. A high level of haplotype diversity (h = 0.618) and a low nucleotide diversity [Dij = 0.00208) were detected in A. podophylla. Populations from Hainan shared common haplotypes with those from Guangdong. A network and a NJ tree constructed from cpDNA haplotypes both suggested a close genetic relationship among populations distributed in Hainan and Guangdong. Observed F ST (=0.10537), gene flow Nm (=2.12), AMOVA (Only 0.49% of variation was partitioned among regions, P -0.09), and DNA divergence data cnnsislciith indicated that no geographical differentiation occured at the interregional level. Geographic isolation has not yet resulted in population differentiations within A. podophylla populations in Hainan and Guangdong. Phylogeographical patterns of atpB-rbcL haplotypes demonstrate a 'star-like' feature, which means that populations of A. podophylla have experienced population expansion, and, since then there has been insufficient time to form a more complicated population structure. The majority of haplotypes coalesced near the tip of the NJ tree, indicating recent coalescence events as well. l analysis of atpB-rbcL sequences of A. podophylla.Alsophila podophylla Hook, is a small tree fern belonging to Alsophila subgenus Gymnosphaera of the Cyatheaceae (Xia, 1989). With erect or tilted trunks, it averages 2 m in height and has 2-pinnate-pinnatind fronds at the apex; its sori are round, lack indusia, and are located on raised receptacles positioned at the base of veins (Chen, 1964). Cyatheoids were globally distributed during the middle Mesozoic. Due to subsequent geologic and climatic changes, many of their ancestral species became extinct. Only some survived in tropical and subtropical montane zones with relictual distributions (Lucansky, 1974; Willis and McElwain, 2002). Extant A. podophylla are mainly restricted to rain forests at altitudes of 350-700 m, growing on shaded meadows, wetlands or by streamsides.