This paper is the survey of the works with T. Adachi, H. Tanabe and M. Kimura. Ruled real hypersurfaces are typical examples of non-Hopf hypersurfaces in a nonflat complex space form. These examples are constructed by the same method in a complex projective space and a complex hyperbolic space. We shall explain geometric properties of ruled real hypersurfaces which depend on the sign of the sectional curvature of those ambient spaces.