Thermal power plant fly ash is one of the most important concerns of this form of energy generation, as it is the most important waste generated by burning coal in a thermal power plant. This kind of fly ash contains elements like Fe, Al, Si, Ca, Na, and K which can be beneficial or harmful to plants depending on the concentration. To evaluate the effect of thermal power plant fly ash on the ecological system, it is necessary to analyze the ecophysiological responses of plants. Zea mays L. (corn) is a worldwide consumed plant species that has been cultivated for 10000 years and it is an important model organism for genetics and biology. In this study, it was aimed that to observe ecophysiological responses of corn against thermal power plant fly ash applications. For the experimental period, control (0 ppm), 500, 1000, 2500, 5000, and 7500 ppm of fly ash applications were set. The experiments took 14 days, and at the end of the experimental period % germination, hypocotyl and radicle lengths, seedling vigor index were calculated. It was observed that 500 to 5000 ppm fly ash applications were stimulated the seed germination, stem and root development, and also seedling vigor index (SVI), but 7500 ppm fly ash applications were inhibited by all ecophysiological parameters. We can say that lower than 5000 ppm fly ash can be useful for agricultural practices, however above 5000 ppm level it is harmful to plant development.