A new species, Takydromus yunkaiensis J. Wang, Lyu, & Y.Y. Wang, sp. nov. is described based on a series of specimens collected from the Yunkaishan Nature Reserve located in the southern Yunkai Mountains, western Guangdong Province, China. The new species is a sister taxon to T. intermedius with a genetic divergence of 8.0-8.5% in the mitochondrial cytochrome b gene, and differs from all known congeners by a combination of the following morphological characters: (1) body size moderate, SVL 37.8-56.0 mm in males, 42.6-60.8 mm in females; (2) dorsal ground color brown; ventral surface green to yellow-green, but light blue-green on chin and throat, posteriorly green in adult males; (3) dorsolateral lines paired, strikingly yellowish-white bordered by black above and below, invisible or indistinct in juveniles and adult females; (4) flanks of body blackish brown with light brown marks in adult males; (5) presence of four pairs of chin-shields; (6) four supraoculars on each side; (7) presence of a row of supracilary granules that separate supracilaries from supraoculars; (8) two postnasals; (9) enlarged dorsal scales in six longitudinal rows on trunk of body, with strong keel; (10) enlarged ventral scales in six longitudinal rows, strongly keeled in males, smooth but outermost rows weakly keeled in females; (11) enlarged and keeled lateral scales in a row above ventrals; (12) femoral pores 2-3 on each side; (13) subdigital lamellae 20-23 under the fourth finger, 23-30 under the fourth toe; and (14) the first 2-3 subdigital lamellae under the fourth toe divided. The discovery of Takydromus yunkaiensis sp. nov. brings the total number of species of this genus to 24, of which nine occur in mainland China. [ABSTRACT FROM AUTHOR]