The Neogene volcanic rocks of Semporna Peninsula is well known for subduction and OIB-like geochemical signature. After the Miocene subduction by the Celebes Sea, subduction-related magmatism was replaced by OIB-like magmatism. The Neogene volcanic rocks in Semporna Peninsula vary from basalt, basaltic andesite, andesite and rhyolite. Major elements and trace elements patterns suggested that the Semporna Peninsula volcanic magma underwent fractional crystallization. From the trend of primitive mantle and REE, 3 types of trends were observed: Subduction-related; depleted Nb, Ta, P, Ti, enrichment of LILE and LREE and depleted in HFSE, OIB-like; enrichment of Nb, Ta and Ti, and MORB; almost flat primitive mantle and REE. The REE patterns also shows the volcanic rocks have Eu negative and positive anomaly, which indicate plagioclase fractionation and plagioclase accumulation. According to the tectonic settings for Semporna Peninsula, the subducted-related volcanic rocks have island arc lavas and plate margin basalt setting. In Triangle FeOT-MgO-Al2O3, the subducted-related volcanic rocks scattered at the orogeny and spreading center islands areas. The tectonic settings for OIB-like (basalt, 18L5; basaltic andesite, 18L9) and MORB (basaltic andesite, 11L5) volcanic rocks are categorized into within-plate basalt and within-plate lavas which occurred in continental setting (Triangle FeOT-MgO-Al2O3).