Abstract
We study the single production of top and fourth standard model family quark t' in ep and γp collisions. The subprocesses eb → t(t')νe and γb → t(t')W for the production of t and t' are considered. We find the total cross-section for single top production as ∼ 38 pb and ∼ 27 pb at future ep and γP colliders with √sep = 5.5 TeV, respectively.