Tianchi volcano in Changbai Mountains is one of the largest active volcanoes on the earth. Its formation and evolution is very complicated. Based on the systematic compilation of drilling cores in and around Tianchi, this study carried out the CZK07 drilling program in this area. We analyzed the compositions of volcanic eruption material under Tianchi volcano cone at Baitoushan stage and the characteristics of volcanic stratigraphic sequences, and manifestation modes of the accompanying volcanism and active characteristics of fault structures during volcanic activities. CZK07 drilling core comprehensively records volcanic stratigraphic sequences of early activities, early and late shieldforming stages, and the preconeforming stage after shieldforming. Among them, early activities in Tianchi volcano are reflected by strongly altered rhyrolite. The early shield formed in the Pliocene, and consists of Junjianshan Formation olivebasalt intercalated with pyroxenebasalt. The latestage shield formed in the early EarlyPleistocene, and consists mainly of Manjiang Formation trachybasalt with intercalation with trachyte. It can be divided into three volcanic activities at least. The preconeforming stage happened in the late EarlyPleistocene and volcanic eruption material consists of trachytic lava and its pyroclastic rock of the Xiaobaishan Formation. The accompanying volcanism includes basaltic subvolcanic rock during the late shield formation, trachytic subvolcanic activity accompanied with alteration and cryptoexplosion during the coneforming stage, and cryptoexplosive breccias, hydrothermal alteration and alkalinerhyolitic subvolcanic activity during the Holocene eruptions. Highangle extensionshear faults were very active since the LateCenozoic in the Tianchi volcano area, inferring that this was closely related to formation of “U” shaped Valley.