The present study evaluated the effects of different light quality on the growth,root activity,pigment content and photosynthetic production of rapeseed (Brassica napus L.) seedlings with pot experiment in order to select a suitable light for rapeseed artificial breeding.Cultivar ‘Ningyou 12’ with two expanded cotyledons were exposed to five lights of fluorescent lamps (FL,control),blue (B) light emitting diodes (LEDs),blue plus red LEDs (BR_1∶1,1∶8) and red LEDs(R).The present results showed that:(1)fresh weight,dry weight,root length,plant height,stem width and leaf area were the greatest in rapeseed seedlings under BR_1∶8 LEDs,which was showed significant differences to FL treatment;(2)root activity was the greatest in rapeseed seedlings under BR_1∶8 treatment,followed by B treatment,which were showed significant differences to FL treatment;(3)the trend of chlorophyll a,chlorophyll b,chlorophyll (a+b) and carotenoid concentrations under five treatment were the same.The values were the greatest in seedlings under B light,followed by BR_1∶8 treatment,which was showed significant differences to BR_1∶1,R and FL treatments;(4)the contents of soluble sugar,starch and amino acid were the greatest in seedlings under BR_1∶8 treatment,which were showed significant differences to BR_1∶1,R and FL treatments;the contents of soluble protein,ascorbic acid and sucrose were the greatest in seedlings under B treatment,which were showed significant differences to BR_1∶1,R and FL treatments;the contents of soluble carbon and nitrogen were the greatest in seedlings under BR_1∶8 treatment,followed by B treatment,which were showed significant differences to BR_1∶1,R and FL treatments;the ratio of carbon and nitrogen was the greatest under FL treatment,which were showed significant differences to other treatments.In general,rapeseed seedlings were grew well;thereby the growth and physiological index were also promoted.The BR_1∶8 and B were the suitable light for rapeseed seedling growth and can be used as a priority light for rapeseed culture system.