This study was conducted to investigate the relationship between the depression of elementary school students and its reflection in Tree-Picture. For the study, 282 students were chosen and got tested Children's Depression Inventory as well as Tree-Picture. The results are as follows. First, there was significant relationship between the depression level and the location of the tree in the picture. The students with higher depression tended to draw tree in the upper-left while the students with lower depression tended to draw tree in the lower-right. Especially the more trees were located in the upper-even- lower than in the right-middle-left. Second, no significant relationship was found between their level of depression and the size of trees or the roots of trees in their drawings. Third, there was significant relationship between the level of depression and certain features of the roots of trees. The students with higher depression tended to draw roots with some of its parts visible above the surface of the soil while the students with lower depression tended to draw root under the surface of the soil. invisible from outside. Trunks were bigger in the pictures of those with higher depression than those with lower depression. These results strongly suggest that the Tree-Test might be useful as a diagnostic device in finding out the children with depression. At the same time, It should be kept in mind that the Tree-Test obviously has some limitations in diagnosing the children with depression.