A method of detecting and analyzing light from a light-emitting particle dispersed and moving at random in a sample solution using an optical system of a confocal microscope or a multiphoton microscope, comprising the steps of: preparing the sample solution containing a light-emitting particle having a first light-emitting site and a second light-emitting site which has a different emission wavelength from that of the first light-emitting site; moving a position of a light detection region of the optical system in the sample solution by changing an optical path of the optical system; and measuring light intensity of the first light-emitting site and light intensity of the second light-emitting site from the light detection region individually and simultaneously with moving the position of the light detection region in the sample solution to individually generate light intensity data; characterized in that the method further comprises the steps of: individually detecting a signal indicating light of a single light-emitting particle in the light intensity data by judging a signal having a bell-shaped profile reflecting the light intensity distribution in the light detection region to correspond to one light-emitting particle having passed through the light detection region, wherein a moving speed of the position of the light detection region is set to be quicker than the average moving speed of a particle by the Brownian motion; and identifying a single light-emitting particle with a ratio of the light intensity of the first light-emitting site and the light intensity of the second light-emitting site in respective signals simultaneously generated on the light intensity data of the first light-emitting site and the light intensity data of the second light-emitting site. preparing the sample solution containing a light-emitting particle having a first light-emitting site and a second light-emitting site which has a different emission wavelength from that of the first light-emitting site; moving a position of a light detection region of the optical system in the sample solution by changing an optical path of the optical system; and measuring light intensity of the first light-emitting site and light intensity of the second light-emitting site from the light detection region individually and simultaneously with moving the position of the light detection region in the sample solution to individually generate light intensity data; individually detecting a signal indicating light of a single light-emitting particle in the light intensity data by judging a signal having a bell-shaped profile reflecting the light intensity distribution in the light detection region to correspond to one light-emitting particle having passed through the light detection region, wherein a moving speed of the position of the light detection region is set to be quicker than the average moving speed of a particle by the Brownian motion; and identifying a single light-emitting particle with a ratio of the light intensity of the first light-emitting site and the light intensity of the second light-emitting site in respective signals simultaneously generated on the light intensity data of the first light-emitting site and the light intensity data of the second light-emitting site.