<b>Oblong Mean Prime Labeling of Some Tree Graphs</b> The labeling of a graph, we mean assign some integers to the vertices or edges or both of the graph. Here the vertices of the graph are labeled with oblong numbers and the edges are labeled with mean of the end vertex labels. Here the greatest common incidence number gcin of a vertex of degree greater than one is defined as the greatest common divisor of the labels of the incident edges. If the gcin of each vertex of degree greater than one is 1, then the graph admits oblong mean prime labeling. Here we characterize some tree graphs for oblong mean prime labeling. Graph labeling, oblong numbers, prime graphs, prime labeling, trees. 222-226 Issue-2 Volume-2 Sunoj B S | Mathew Varkey T K