Steady non-similarity thermal boundary layer flow over a stretching flat plate is investigated. The velocity and temperature on the surface are assumed to vary with the distance. The energy equation is solved with the homotopy analysis method which is suitable for strongly non-linear problems. This approach is more general than the similarity methods and is valid in the whole spatial and temporal regions. The results are compared with the similarity solutions for special cases of velocity and temperature profiles on the wall. The effect of different parameters on the Nusselt number and temperature profiles is investigated.