Yildirim, Mehmetİlarslan, Kazim2025-01-212025-01-2120190354-5180https://doi.org/10.2298/FIL1917743Yhttps://hdl.handle.net/20.500.12587/23561The present paper mainly deals with construction and investigation further properties of semi-parallel and harmonic surfaces. The first part of the study shall be devoted to investigate and present necessary and sufficient conditions of being semi-parallel surfaces by considering semi-parallelity condition R(X, Y).h = 0. In the light of the condition, the fact of a part of semi-parallel surfaces can be created by translation surfaces is captured. As a last result, we present that M must be a translation surface in the case of it is a harmonic surface. © 2019, University of Nis. All rights reserved.eninfo:eu-repo/semantics/openAccessHarmonic surface; Semi-Euclidean space; Semi-parallel surface; Translation surfaceArticle33175743575310.2298/FIL1917743Y2-s2.0-85077842296Q3