Abstarct: In this thesis, we study the zero-divisor graphs of posets. First, we focus on the coloring of these graphs. It will be shown that the clique number and chromatic number of these graphs are equal. Also, we study the diameter and girth of the zero-divisor graphs of posets. Next, we classify all posets whose zero-divisor graphs are planar or complete partite. Finally, we charactrise all graphs that are zero-divisor graphs of posets.