We denote by Mm(c') an m-dimensional simply connected and complete K~ihler manifold of constant holomorphic sectional curvature 6, which is called a complex space form. Let Pm(C) be an m-dimensional complex projective space endowed with a Fubini-Study metric. Then Pm(C) is a complex space form of positive holomorphic sectional curvature. A complex Euclidean space (12 m endowed with the usual Hermitian metric is a complex space form of zero holomorphic sectional curvature. An open unit ball D m in ~m endowed with the natural complex structure and the Bergmann metric is a complex space form of negative holomorphic sectional curvature. Any m-dimensional complex space form /Qm(c') is (after multiplying the metric by a suitable constant) complex analytically isometric to P~(~), ~'~, or D m according as the holomorphic sectional curvature 6 is positive, zero, or negative.By a Kfihler submanifold we mean a complex submanifold with the induced Kfihler metric. We consider Kfihler submanifolds in a complex space form which are Einsteinian with respect to the induced metric. Einstein K~ihler hypersurfaces in a complex space form are completely classified by Smyth [5] and Chern [1]. That is, an n (>2)-dimensional Einstein Kfihler hypersurface M in a complex space form M" § 1(6) is totally geodesic if 6<0 and is either totally geodesic or locally a complex hyperquadric Q,(~) if 6 > 0. In this note we consider the case of codimension 2 and show the following.
Theorem. Let M be an n (> 2)-dimensional Einstein Kdhler submanifold immersed in~,+z(~. If 6<0, then M is totally 9eodesic. If 6>0, then M is either totally 9eodesic or locally a complex hyperquadric Q,(C) in P,+I(~) which is totally geodesic in P, + z(~).Remark 1. When n = 2, the above result is already shown by Matsuyama [2].Remark 2. If we replace our assumption on the Ricci tensor in the theorem by a weaker one that the Ricci tensor is parallel, an open submanifold of PI(C) x P2(C) in Ps(~) is only added in the conclusion of the theorem. The immersion of Pt(~)