We study a topological sigma-model (A-model) in the case when the target space is an (m0|m1)-dimensional supermanifold. We prove under certain conditions that such a model is equivalent to an A-model having an (m0 − m1)-dimensional manifold as a target space. We use this result to prove that in the case when the target space of A-model is a complete intersection in a toric manifold, this A-model is equivalent to an A-model having a toric supermanifold as a target space.Our goal is to study a two-dimensional topological σ-model (A-model). Sigma-models having supermanifolds as target spaces were considered in an interesting paper [5]. However, the approach of [5] leads to a conclusion that in the case when the target space of A-model is a supermanifold the contribution of rational curves to correlation functions vanishes (i.e. these functions are essentially trivial). In our approach A-model having a (m 0 |m 1 )-dimensional supermanifold as a target space is not trivial, but it is equivalent to an A-model with (m 0 − m 1 )-dimensional target space. We hope, that this equivalence can be used to understand better the mirror symmetry, because it permits us to replace most interesting target spaces with supermanifolds having non-trivial Killing vectors and to use T -duality.We start with a definition of A-model given in [1]. This definition can be applied to the case when the target space is a complex Kähler supermanifold M . Repeating the consideration of [1] we see that the correlation functions can be expressed in terms of rational curves in M , i.e. holomorphic maps of CP 1 into M . (We restrict ourselves to the genus 0 case and assume that the situation is generic; these restrictions will be lifted in a forthcoming paper [8]).Let us consider for simplicity the case when (m 0 |m 1 )-dimensional complex supermanifold M corresponds to an m 1 -dimensional holomorphic vector bundle α over an m 0 -dimensional complex manifold M 0 (i.e. M can be obtained