Located at the western end of the gold ore cluster area in the northwestern Jiaodong Peninsula, the Sanshandao gold metallogenic belt is an important gold ore belt in the Jiaodong Peninsula, which hosts several large- scale and super- large gold ore deposits in Sanshandao and its northern part, Xiling, Xinli and Cangshang. Ore-controlling country rock of the gold deposits is monzogranite. This study carried out geochemistry analysis, zircon LA-ICP-MS U-Pb dating and Lu-Hf isotopic composition of Cangshang gneissic biotite monzogranite and Sanshandao porphyritic-like biotite monzogranite to discuss petrologic classification, forming age, magma source regions and genesis of the rocks. Lithogeochemical analysis shows that the monzogranites are high in SiO2(70.19%～76.36%), total alkalis (Na2O+K2O=7.05%～8.19%), Ba(>1573×10-6), Sr(>738×10-6), (La/Yb)N(>26.44), Sr/Y(>121), LILE /HFSE, and low in Al2O3(13.41%～15.61%), MgO(0.1%～0.84%), Y(<6.05×10-6), Yb(<0.53×10-6), with relatively flat HREE, no obvious Eu anomaly. The rocks are characterized by prominent depletion of Nb, Ta, P and Ti, presenting geochemical feature of typical high BaSr granite. All these features indicate that the rocks belong to the high BaSr granites. LA- ICP- MS zircon dating yields the U- Pb ages of 131±1 Ma and 127±2 Ma for Cangshang and Sanshandao monzogranites, respectively. The Cangshang and Sanshandao monzogranites have similar major elements compositions, REE and trace element distribution patterns as the Guojialingtype granitoid granites, suggesting that Cangshang and Sanshandao monzogranites are Guojialingtype granitoid granites. The Cangshang and Sanshandao monzogranites have zircon εHf(t) values of-25.2 to -18.1, and corresponding two- stage Hf model ages (TDM2) range from 2.77 to 2.33Ga. Based on previous studies on the genesis of the Guojialing granite and the results obtained in this study, it can be concluded that the Cangshang and Sanshandao monzogranites were the products of mixture between crustal felsic magma and mantle intermediatemafic magma, i.e. syntexis plutonic granites formed by differentiation after the mixture of the crustal magma (mainly originated from the Precambrian metamorphic basement rocks consisting of NeoarcheanPalaeoproterozoic rocks), and mantle intermediatemafic magma in a high temperature and deep environment.