Located on the southeast coast of Fujian Province, Taimushan granite was formed as a result of the interaction between the Pacific plate and the Eurasian plate during the late Mesozoic. Field work and petrographic analysis show that granite rocks are extensively distributed in this area, and most of them are K-feldspar granite. Rocks mostly show subhedral granular texture and typical micrographic texture, and the main minerals include alkali feldspar (mainly perthite and subordinately a small amount of microcline) and quartz, with very rare dark minerals. The SiO₂ content of rocks is in the range of 76.93%～79.47%, the total alkalis content (K₂O+Na₂O) is in the range of 7.47%～8.88%, and the K₂O content of most rocks is higher than Na₂O content. A/CNK ratios are in the range of 0.95～1.01, TFeO/MgO ratios are in the range of 8.11～17.83, and the differentiation index is in the range of 96.79～98.11. On the whole, the rocks are characterized by high silicon, enrichment of alkali, low calcium and magnesium, and high differentiation index, thus belonging to high-K calc-alkaline and metaluminous to weakly peraluminous granitoids. The rocks have high and remarkably varying REE, ranging from 94.98×10^-6 to 446.85×10^-6; LREE/HREE ratios range from 3.71 to 17.47, and (La/Yb)_N range from 3.8 to 10.53. δEu values range from 0.08 to 0.80, and their distribution patterns show LREE enrichment with gentle right oblique deviation, relative flat HREE and a seagull model characterized by significant negative Eu anomaly, suggesting characteristics of A-type granitic rocks. Most of the granites are strongly enriched in Rb, U, Th and La and considerably depleted in Ba, Sr, P and Ti. 10⁴ Ga/Al ratios are distributed between 2.74 and 3.46 (3.14 on average), which are higher than the 10⁴ Ga/Al low limit ratio of A-type granites in the world. The trace element spider diagrams of the granites generally show four V-shaped valleys for Ba, Sr, P, Ti depletion, similar to trace element spider diagrams of the Nanling granites. Zircon LA-ICP-MS U-Pb dating result indicates that Taimushan granite, whose diagenetic age is 96.6±1.6 Ma (MSWD=0.65), is the product of magmatic activity in late Yanshanian period. Its petrogenic age is similar to rock-forming ages of the adjacent Sanshao (91.5±1.5 Ma), Dacengshan (93.1±2.4 Ma) and Nanzhen intrusive bodies (96.1±2.7 Ma), suggesting that they may be products of the same magmatism. Petrography, geochemistry and discrimination diagrams show that the Taimushan granitoids belong to A-type granite with metaluminous to weakly peraluminous characteristics. Magma originated from partial melting of crustal materials, probably with the participation of a small portion of mantle materials. Integrated with multiple geochemical diagrams, field geology, regional background and geochronology, it is inferred that the granitic rocks of this area were formed in a post-collision and tensile tectonic environment. Between early and late Cretaceous, the continental margin of southeast China was constantly stretching, resulting in a large number of magmatic activities, and hence A-type granites were formed in Taimushan area under this background.