In recent years, changing climatic conditions have brought along many problems. As a result of the increasing destruction of the ozone layer caused by anthropogenic sources, the effect of harmful sun rays reaching our world is increasing. It is estimated that the temperatures on the earth's surface and ultraviolet-B (UV-B) radiation will increase in the coming years due to global climate change. This study used ash-leaved maple (Acer negundo) and sycamore maple (Acer pseudoplatanus) seedlings to examine the effects of drought and UV-B radiation levels that may occur in the coming years on forest trees. The study investigated the effect on stomatal characters by applying two different doses of UV-B and drought stress. As a result of the study, it was determined that UV-B stress had a more significant effect on stomatal characters than drought stress. It has been observed that severe drought generally reduces the number of stomata. It was determined that the sycamore maple was more affected by severe drought and UV-B radiation. While UV-B radiation decreased only the stomatal pore length and width in sycamore maple, it increased the stomatal pore length and width in ash-leaved maple. The response of stomatal characters to drought and UV-B stress remains unclear. Therefore, more detailed studies are required.