Let X be topological vector space with Baire topology and B(X) = {A (?) X: A Satisfies the Condition of Baire}

then B (X) is a σ- algebra.In this paper we give a notion of measurability for the mapping f: X→Y(whereY is a topological space) is called measurable by Baire Condition

if f-1 (V) ∈B(X) for every open set V (?) Y. And we prove a theorem as follows: Theorem: Suppose that f: X→R is Jensen Convex function

then f is continuouson X if and only if f is measurable by Baire Condition.