A biological observation system includes: a light source section configured to supply illumination light applied to a region to be observed including biological tissue, the illumination light including first illumination light that is one of red light and near infrared light in a visible region and second illumination light that is light in the visible region different from the first illumination light a light detection section configured to receive return light emitted from the region to be observed and output an output signal a signal processing section configured to output a frequency spectrum signal indicating a frequency spectrum obtained by analyzing a frequency of the return light emitted from the region to be observed according to application of the first illumination light an image generation section configured to generate an intensity image based on the output signal and generate a frequency spectrum image based on the frequency spectrum signal and a display control section configured to generate and display an observation image of the region to be observed by using the intensity image and the frequency spectrum image.
