Berndt and Vanhecke1 have introduced two new classes of Riemannian man
ifolds (C-spaces and B-spaces) including locally symmetric spaces. On
one hand, a Riemannian manifold satisfying the condition R(X, Y) . R =
0 is called a semi-symmetric space. A locally symmetric space is nece
ssarily a semi-symmetric space. In this paper, we shall study semi-sym
metric B-spaces (resp. C-spaces).