In the southern Sulu orogenic belt, old supracrustal rocks and granitic intrusions were subjected to ultrahigh-pressure metamorphism (UHPM) in 220 to 240 Ma during the subduction and collision between the North China plate and Yangtze plate, and then amphibolite-facies retrogression during the exhumation of UHPM rocks. Based on the study of petrology and petrochemistry, these rocks can be divided into six types, i. e. eclogite, garnet peridotite, quartz jadeitite, garnet-phengite schist, jadeite quartzite and garnet and omphacite-bearing aragonite marble. They were transformed to amphibolite, serpentinite, gneiss, quartz-mica schist, quartzite and marble during the amphibolite-facies retrogression. The chemical characteristics indicate that the protolith of eclogites were possibly tholeiite with a continental affinity, whereas the garnet peridotites were derived from a depleted mantle. The protoliths of quartz jadeitite include metamorphosed granite, trondhjemite, acidic volcanic rocks and feldspar-quartz sandstone. The metamorphosed granites show an affinity of continental or continental margin. The quartz-mica schist, quartzite and marble were metamorphosed sedimentary rocks, and, together with paragneiss and mafic rock, constituted the old supracrustal series. The bimodal association of acidic and mafic volcanic rock suggests that some supracrustal rocks were formed under continental rift. Therefore, the protoliths of the UHPM rocks from the southern Sulu orogenic belt were sedimentary rocks, mafic and acidic volcanic rock, granite and trondhjemite formation with continental affinity.