Consider the differential equation −y′′ + q(x)y = λ2ρ(x)y, 0 < x < ∞ (1) with boundary condition −(α1y(0) − α2 y′(0)) = λ2(β1 y(0) − β2 y′(0)). (2) Here q(x) is a real valued function such that ∫ ∞ 0 (1 +x)|q(x)|dx < ∞ and ρ(x) is a real valued piecewise continuous function. It is known that the boundary value problem (3)-(4) has only finite number of simple negative eigenvalues −µ21, · · · ,−µ2n, (µ j > 0) and the half axis constitutes absolutely continuous spectrum. For normalized eigenfunctions of the problem (3)-(4) we have the asymptotic formulae as x→∞ u j(x) ∼ m je−µ jx, j = 1, . . . ,n, u(λ, x) ∼ e−iλx − S(λ)eiλx, −∞ < λ < ∞. So at infinity behaviour of the radial waves is defined by {S(λ) (−∞ < λ < ∞),−µ2k , mk (k = 1 . . . n)}. These are called scattering data of the (3)-(4) boundary value problem. In this work characteristic properties of the scattering data will be investigated.