A living body observation system of the present invention includes an illumination unit for sequentially emitting as an illumination light a plurality of broad band lights and at least one narrow band light to a subject in a living body to illuminate the subject an image pickup unit for picking up each image of the subject illuminated by the illumination unit and outputting the image as an image pickup signal a first image generation unit for, based on the image pickup signals, generating a first observation image according to the plurality of broad band lights, and generating a second observation image according to at least one broad band light of the plurality of broad band lights, and the at least one narrow band light, using predetermined signal processing and a second image generation unit for combining the first observation image and the second observation image to generate one image.
