Title: Note on the mod p motivic cohomology of algebraic groups. Author: Nobuaki Yagita AMS classification numbers: 55P35, 57T25. Adress of Author: Faculty of Education, Ibaraki University, Ibaraki, Japan. Author's e-mail address: yagita@mx.ibaraki.ac.jp Abstract: Let G_k be a split reductive group over a field k of ch(k)=0 corresponding to a compact Lie group G. In this paper, we show that the mod p motivic cohomology is isomorphic to the tensor product of the usual mod p cohomology H^*(G;Z/p) and the motivic cohomology H^{*,*'}(Spec(k);Z/p), when G=SO_n,G_2,F_4,E_6. We also give an example of nonsplit case (G=G_2,p=2,k=R) which does not hold the above isomorphism.