PROBLEM TO BE SOLVED: To provide an endoscope system and light source device capable of improving color separation property and visibility of the surface-layer blood vessel in a narrow band imaging using a complementary color type imaging device.SOLUTION: Purple narrow-band light Vn and green narrow-band light Gn generated by a light source device are supplied to a complementary color type endoscope and simultaneously applied to the interior of a test body. A first mixed pixel and a second mixed pixel sensitive to both of the purple narrow-band light Vn and green narrow-band light Gn are read from a complementary color type imaging device. A light quantity ratio Z of a light quantity of the purple narrow-band light Vn to a light quantity of the green narrow-band light Gn is set to within a prescribed range based on an optimal light quantity ratio Zthat matches a ratio P1 of components of the purple narrow-band light Vn in a first mixed pixel signal, with a ratio P2 of components of the green narrow-band light Gn in a second mixed pixel signal.【課題】補色系撮像素子を用いた狭帯域光観察において、色分離性を向上させることを可能とする内視鏡システム及び光源装置を提供する。【解決手段】光源装置により生成される紫色狭帯域光Ｖｎ及び緑色狭帯域光Ｇｎは、補色型内視鏡に供給されて、検体内に同時照射される。補色系撮像素子からは、紫色狭帯域光Ｖｎと緑色狭帯域光Ｇｎとの両方に感応する第１混合画素と第２混合画素とが読み出しされる。緑色狭帯域光Ｇｎの光量に対する紫色狭帯域光Ｖｎの光量の光量比Ｚは、第１混合画素信号中の紫色狭帯域光Ｖｎの成分の割合Ｐ１と、第２混合画素信号中の緑色狭帯域光Ｇｎの成分の割合Ｐ２とを一致させる最適光量比Ｚ０を基準とした所定の範囲内に設定されている。【選択図】図１６
