Thenewly discovered ore blocks in the Jiama mining area related to the No. II complex massif are located in northern Zegulang that lies in the northeast of the Jiama mining area. Geological surveys and drilling data reveal thatthe No. II complex massif includes many kinds of rocks such as granite porphyry, granodiorite- porphyry, monzoniticgraniteporphyry, quartz diorite porphyrite etc., with thick copper and molybdenum ores. To obtainthe diagenetic time and petrogenesis of the No. Ⅱcomplex massif, zircon LA- ICP- MS U- Pb chronology and primary and trace geochemical analyses of the granite porphyry are carried out in this paper. The result show that the zircon U- Pb age of granite porphyry is 15.7±0.3 Ma (n=22, MSWD=3.3) which is consistent with theemplacement age of the ore- bearing porphyry in the main ore blocks. Meanwhile, thegranite porphyrythat is the product formed by melting of crust- derived sandy sedimentary rocks in the post- collision environment, has the characteristics of high silicon, high potassium, and high aluminum, and is obviously enriched in light rare earth and large ion lithophile elements with inconspicuous Eu anomaly, abnormal weak and negative Ce, and high differentiation indexes. In addition, as a newly discovered ore block, the No. II complex massif has the potential to be a large- to- super- large- scale deposit and is considered as an important target area for the follow- up exploration evaluation because of uncovering of surficial “limonite coverage” with large area, deep thick porphyry ore bodies and hornstone ore bodies.