A lighting apparatus for growing plants is disclosed. The apparatus includes a first light source generating a first peak spectrum, a second peak spectrum and a third peak spectrum. The first peak spectrum ranges between 350nm and 500nm with FWHM less than 50nm and a first (relative quantity) level. The second peak spectrum ranges between 500nm and 570nm with FWHM ranges between 50nm and 100nm and a second (relative quantity) level. The third peak spectrum ranges between 600nm and 700nm with FWHM ranges between 50nm and 100nm and a third (relative quantity) level. A ratio of the first and second level ranges between 1 and 10.本案係提供一種植物生長照明裝置,其包括第一光源單元。第一光源單元產生第一輸出光譜包含第一峰值波段、第二峰值波段及第三峰值波段。其中第一峰值波段介於350nm至500nm之間,其半波寬小於50nm,且具有第一峰值相對強度。第二峰值波段介於500nm至570nm之間,其半波寬介於50nm至100nm之間,且具有第二峰值相對強度。第三峰值波段介於600nm至700nm之間,其半波寬介於50nm至100nm之間,且具有第三峰值相對強度。其中第三峰值相對強度與第二峰值相對強度之比值介於1至10之間。11‧‧‧第一輸出光譜111‧‧‧第一峰值波段112‧‧‧第二峰值波段113‧‧‧第三峰值波段I1‧‧‧第一峰值相對強度I2‧‧‧第二峰值相對強度I3‧‧‧第三峰值相對強度
