A new reed snake of the genus Calamaria Boie, 1827, Calamaria andersoni, new species, is described on the basis of a single male specimen collected from Yingjiang County, Yunnan Province, China. The new species can be distinguished from other congeners by the unique combination of the following morphological characters: nine modified maxillary teeth; four supralabials, second and third supralabials entering orbit; one preocular; mental not touching anterior chin shields; six shields and scales surrounding the paraparietal; dorsal scales in 13:13:13 rows; 171 ventral scales; 23 subcaudals; tail slowly tapering anteriorly, then abruptly tapering at tip; dorsal scales reduced to four rows on tail at last two subcaudals; dorsum of body and tail brownish with indistinct narrow black stripes on sides; dark collar on neck absent; light rings/blotches on neck and tail absent; and ventral scales with dark outermost corners. Calamaria andersoni, new species, is the fourth species of the genus recorded from China.