In this paper we define and examine the truncated Witten genus. It is defined as the equivariant index of the Dirac operator on the manifold Map(Cp, M) with its natural Cp-action. Here, Map(Cp, M) is the space of maps from the cyclic group of order p into a closed, connected, spin manifold, By applying the Atiyah-Singer index theorem we give a topological formula for the truncated Witten genus ...