Objectives: Liaodong peninsula is always a hot spot area for study of North China Craton （NCC） thinning. Previous researcher still have a disagreenment on tectonic environment in Liaodong peninsula. Metheods: We select biotite monzogranite outcropped in Houbiangouling and quartz monzodiorite outcropped in Daheikeng, Xiuyan area, eastern Liaoning province, to be studied by using LA- ICP- MS zircon U- Pb chronology and Petrogeochemistry. Results : In addition, the origin and formation environment of the above two plutons are discussed and work out the following results: the formation age of Houbiangouling biotite monzogranite and Daheikeng quartz monzodiorite is Late Triassic(220.9±1.2 Ma and 220.3±1Ma); the geochemical characteristic of Houbiangouling biotite monzogranite has high content of SiO2, riched in alkali; the Daheikeng quartz monzodiorite has high content of Mg, the obvious fractional distillation of LREE, but HREE is not obvious; the Houbiangouling biotite monzogranite and Daheikeng quartz monzodiorite have similar characteristics in rare earth elements and trace elements, both of them show characteristics of light rare earth obvious fractionation, while heavy rare earth fractionation was not obvious, and are enriched in large ion lithophile elements Rb, K, loss Ba, Sr; and enriched in high field intensity elements Th, La, Ce, Nd, Hf, Tb, while loss P, Nb, Ta, Y. Conclusions: Both of them have the same magmatic source and the characteristics of crust—mantle magama mixture; the probable tectonic background is crustal extension and thinning in Xiuyan area, eastern Liaoning province during 220.9±1.2 Ma～220.3±1.0 Ma; the Houbiangouling biotite monzogranite and Daheikeng quartz monzodiorite formed in the crustal extension and thinning tectonic background. The formation of the Houbiangouling biotite monzogranite and Daheikeng quartz monzodiorite are relate to North China Craton thinning caused by continental collision orogeny between Yangtze Craton and North China Craton.