Let Mn be the algebra of all n×n complex matrices.It is proved that a non-zero linear map Φ on Mn preserving the self-Jordan products, that is Φ(A* ∘A) = Φ(A)* ∘(A) for all A ∊ Mn, if and only if there is a unitary matrix U in Mn such that Φ(X) = UXU*, ∀ X ∊ Mn, or Φ(X) = UXT U*, ∀X ∊ Mn, where XT denotes the transpose of matrix X.