An optical analysis device configured to detect and analyze 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: a light detection region moving means configured to move a position of a light detection region of the optical system in the sample solution by changing an optical path of the optical system at a speed sufficiently higher than the diffusional moving velocity of the light-emitting particle; and a light detecting means configured to detect intensities of components of two or more wavelength bands of light from the light detection region; further comprising: a signal processing means configured to detect individually signals from each light-emitting particle in the intensities of the components of the two or more wavelength bands of the light detected with the light detecting means with moving the position of the light detection region in the sample solution by generating time series light intensity data of the components of the two or more wavelength bands of the detected light, smoothing the time series light intensity data so that gaps in the data value can be disregarded, computing a first differentiation value with time of the smoothed time series light intensity data for identifying respective start points and respective end points of pulse existing regions in which significant pulse form signals exist, and by then individually detecting, in the pulse existing regions of the smoothed time series light intensity data, a variation in time of the light intensity data having a profile expected for light from each light-emitting particle which moves relatively inside the light detection region as the signal of the light-emitting particle, and identifying a kind of the detected light-emitting particle based on the intensities of the components of the two or more wavelength bands of the signals of the light from each light-emitting particle. a light detection region moving means configured to move a position of a light detection region of the optical system in the sample solution by changing an optical path of the optical system at a speed sufficiently higher than the diffusional moving velocity of the light-emitting particle; and a light detecting means configured to detect intensities of components of two or more wavelength bands of light from the light detection region; further comprising: a signal processing means configured to detect individually signals from each light-emitting particle in the intensities of the components of the two or more wavelength bands of the light detected with the light detecting means with moving the position of the light detection region in the sample solution by generating time series light intensity data of the components of the two or more wavelength bands of the detected light, smoothing the time series light intensity data so that gaps in the data value can be disregarded, computing a first differentiation value with time of the smoothed time series light intensity data for identifying respective start points and respective end points of pulse existing regions in which significant pulse form signals exist, and by then individually detecting, in the pulse existing regions of the smoothed time series light intensity data, a variation in time of the light intensity data having a profile expected for light from each light-emitting particle which moves relatively inside the light detection region as the signal of the light-emitting particle, and identifying a kind of the detected light-emitting particle based on the intensities of the components of the two or more wavelength bands of the signals of the light from each light-emitting particle. a signal processing means configured to detect individually signals from each light-emitting particle in the intensities of the components of the two or more wavelength bands of the light detected with the light detecting means with moving the position of the light detection region in the sample solution by generating time series light intensity data of the components of the two or more wavelength bands of the detected light, smoothing the time series light intensity data so that gaps in the data value can be disregarded, computing a first differentiation value with time of the smoothed time series light intensity data for identifying respective start points and respective end points of pulse existing regions in which significant pulse form signals exist, and by then individually detecting, in the pulse existing regions of the smoothed time series light intensity data, a variation in time of the light intensity data having a profile expected for light from each light-emitting particle which moves relatively inside the light detection region as the signal of the light-emitting particle, and identifying a kind of the detected light-emitting particle based on the intensities of the components of the two or more wavelength bands of the signals of the light from each light-emitting particle.