In this talk, we consider tilings on surfaces (2-dimensional manifolds without boundary). If the face-cycle at all the vertices in a tiling are of same type then the tiling is called semi-regular. In general, semi-regular tilings on a surface M form a bigger class than vertex-transitive and regular tilings on M. This gives us little freedom to work on and construct semi-regular tilings. We present a combinatorial criterion for tilings to decide whether a tiling is elliptic, flat or hyperbolic. We also present classifications of semi-regular tilings on simply-connected surfaces (i.e., on 2-sphere and plane) in the first two cases. At the beginning, we present some examples and brief history on semi-regular tilings.