  In the paper the covariant kernel of the nucleon-nucleon interaction of
particles with scalar propagators is analyzed. The Bethe-Salpeter equation for
the T matrix is considered in the rank- one separable kernel. The parameters of
the kernel for the specific partial-wave channels explicitly connect with the
observables { low energy scattering parameters and phase shifts, deuteron
binding energy. Covariant separable kernels forthe partial-wave channels with
total angular momentum J = 0 (1S0, 3P0) and J = 1 (3S1 -3D1, 1P1, 3P1) are
constructed.
