In this paper, we analyze the non-selfadjoint Sturm-Liouville operator L defined in the Hilbert space L 2 (R, H) of vector-valued functions which are strongly-measurable and square-integrable in R. L is defined L(y) = −y ′′ + Q(x)y, x ∈ R, for every y ∈ L 2 (R, H) where the potential Q(x) is a non-selfadjoint, completely continuous operator in a separable Hilbert space H for each x ∈ R. We obtain the Jost solutions of this operator and examine the analytic and asymptotic properties. Moreover, we find the point spectrum and the spectral singularities of L and also obtain the sufficient condition which assures the finiteness of the eigenvalues and spectral singularities of L.