||Due to the unique and useful optical properties of Quantum Dots, basic physical and interaction studies with other materials have been actively conducted. The fluorescence wavelength at the QDs depends on the size of the particles, even if it consists of the same material. The smaller the particle size, the shorter the wavelength, and by adjusting the size, the more fluorescence in the visible light domain of the desired wavelength can be produced. Here, we describe one-pot synthesis of water-soluble fluorescent iron selenide(FeSe). To verify the size of FeSe and the degree of quantum yield according to the reaction time, time-based samples have been synthesized. The sample with the longest response time display fluorescence more clearly at an excitation wavelength of 365nm. Availability of one-pot synthesis of water-soluble Fluorescent FeSe is expected to stimulate further studies of these materials in chiral quantum dots.