Shahewan rapakivi granite which intruded into the Qinling orogenic belt in 195~213 Ma is a young intrusion. The type, chemical composition andt—pcondition of biotite from this rapakivi granite are discussed in this paper. The biotite is Mg_Fe biotite, which has higher Mg than biotite from S_type and I_type granite. FeO and Al2O3of this granite is similar to those of I-type granite. Si is from 2.99 to 2.6, higher than Si of A-type granite and lower than that of I-type granite. Al2O3and TiO2show negative correlation, being similar to character of biotite from A_type granite. The crystalline condition of biotite ist=750~820℃and logfO2 =-8.5 ~-9.5, which are higher than the values in average granite.p=0.1 GPa±. The above character indicates that biotite of Shahewan rapakivi granite is different from biotite from S-type and A-type granite as well as I-type granite, showing that this rapakivi granite is a transitional type between I-type granite and A-type granite and is a product of special tectonic condition. The result is consistent with conclusions from our other studies and is also supported by researches on other rapakivi granites. In short, our studies show that chemical composition of biotite can determine type of gra-nite and provide information for the formation environment of the intrusion.