Many researches on the granitoids in most area of the Chinese Altai have been carried out, but retracing the entire tectonomagmatic evolutionary history of the Chinese Altai orogen is still being restricted due to the lack of understanding on the southeastern Altai. This study is based on four samples of granitic plutons (Kungeyite, Kujierte, Butiewu and Kalateyubie), zircon U-Pb (LA-ICP-MS) dating yields the ages of 382±4Ma, 381±4Ma, 385±5Ma and 363±6Ma, respectively. These granitic rocks belong to highK calcalkaline and metaluminousweakly peraluminous series of type I, depending on their petrological and geochemical characteristic. They have negative whole rock εNd(t) values of -2.42~-0.53 with Nd model ages tDMof 1.6~1.3Ga and zircon εHf(t) values of -3.43~+12.89 (mostly positive), with Hf model ages tDM-2of 2.5~0.6Ga, suggesting complex sources. These data indicates mantlederived substances involved during the process of generation of granitoids as well as ancient crustal compositions. The Devonian granitic rocks in the Chinese Altai can be classified as Early Devonian (420~390Ma) and MiddleLate Devonian (390~360Ma); the former is mostly calcalkaline series of metaluminousperaluminous and the latter is highK calcalkaline series of metaluminousweakly peraluminous. It provides new evidence for the features of evolvement of the EarlyMiddle Devonian granitoids from calcalkaline series (480~390Ma) to highK calcalkaline series (390~360Ma), then to alkine granite (354Ma), because of the certainty of highK calcalkaline granitic rock (363Ma) in this area. This evolvement further confirmed the evolution process of the Chinese Altai are consistent with tectonic settings from subduction to collision and then to postcollision extentional environment. Combined with the analysis of isotope and regional geological data, we conclude that the MiddleLate Devonian granitoids in the southeastern Chinese altai are active continental arc environment in the background of subduction. The Late Devonian granitoids have the characteristics of collision, followed by the Early Carboniferous postcollision alkaline granite.