The present invention provides: an aminocoumarin compound having a structure represented by the following formula (1); and an aminocoumarin compound-containing resin particle containing the aminocoumarin compound and a resin particle containing the aminocoumarin compound. In formula (1), Rs each independently represent a hydrogen atom or a methyl group, Q represents a sulfur atom, an oxygen atom, or N—R1, and R1 represents a hydrogen atom or a methyl group. The aminocoumarin compound of the present invention is a fluorescent dye that has a longer excitation wavelength than a conventionally known sulfonated coumarin-based compound and is effectively excited at a wavelength of 475 nm or more, particularly at a wavelength around 500 nm. The aminocoumarin compound of the present invention is a fluorescent dye that is excited, for example, at a wavelength of 475 to 510 nm and can be observed in a green light emission region of 510 to 540 nm using the wavelength characteristic, and can be expected to be suitably utilized in immunostaining or the like.