The ancient rock paintings drawn with ochre on the limestone cliffs at 15 sites in Cangyuan County, in southwestern China, contain more than 1200 identifiable figures. The paintings portray scenes of daily life in a remote mountainous area. The inhabitants probably led a sedentary life of animal herding and cultivation and in the scenes they are engaged in activities such as dancing, hunting and fighting. These rock paintings have been known more than 50 years, and have been registered by the State Council of China as major cultural relics under national protection since 2001, but their ages have remained uncertain. In this study, we carried out MC-ICPMS U-series (n = 57) and AMS 14C (n = 4) dating of the carbonate accretions associated with the rock paintings at eight sites. Among them, 25 samples overlying pigment and 14 samples underlying pigment with insignificant initial 230Th contamination yielded highly precise U-series ages. The samples overlying pigment provided reliable minimum ages of 3760, 2920, 2680 and 1110 yr BP for the dated motifs at Sites 2, 7, 14, and 11, respectively. The age ranges for the underlying carbonate accretions overlap those of the overlying ones, from ~3800 to ~3200 yr BP at Site 2 and from ~3000 to ~2700 yr BP at Site 7, suggesting that rock painting was a long-lasting tradition in this region. The combination of all of the reliable U-series dates enables us to constrain the time interval of the main rock painting phase to ~3800–2700 yr BP, which is coeval with the regional late Neolithic culture.