Abstract
We study the non-lightlike ruled surfaces in Minkowski 3-space with non-lightlike base curve c(s) = integral(alpha t + beta n + gamma b) ds, where t, n, b are the tangent, principal normal and binormal vectors of an arbitrary timelike curve Gamma(s). Some important results of flat, minimal, II-minimal and II-flat non-lightlike ruled surfaces are studied. Finally, the following interesting theorem is proved: the only non-zero constant mean curvature (CMC) non-lightlike ruled surface is developable timelike ruled surface generated by binormal vector.