This study was conducted to investigate the effects of directive sand tray play on the parenting stress of mothers with depressive tendency. In particular, the study aimed to, firstly, confirm the effect of the directive sand tray play on the parenting stress of mothers with depressive tendency, and secondly, to clarify the effect of directive sand tray play on the linguistic expression of mothers with depressive tendency. The directive sand tray play consisted of program interpretation, exploration stage, recognition stage, execution stage, and finishing. The change in the parenting stress of mothers with depressive tendency was measured by comparing their scores in the self-reporting parenting stress test before, after, and at a program follow-up. In order to recognize changes in linguistic expression, we measured, analyzed, and qualitatively described changes in and out of the directive sand tray play session. The results of this study are as follows: First, the directive sand tray play reduced parenting stress on the self-reported measure of mothers with depressive tendency; second, the directive sand tray play increased mothers’ positive expression and decreased negative expression in and out of the session. This study a small number of case studies using a multiple probe baseline design, and directive sand tray play is significant in that it has been confirmed to reduce the parenting stress of mothers with depressive tendency.