Abstract: To investigate the effects of different LED light sources on contents of IAA， GA3， ABA， and ZR in non\|heading Chinese cabbage and tomato， the plants were cultured under five light quality treatments: yellow LED （Y）， green LED （G）， red LED （R）， blue LED （B）， red plus blue LED （R∶B=6∶1）， while the sunlight dysprosium lamp （CK） was used as control. Meanwhile， the effects of different densities of red plus blue light on endogenous hormones content of tomato were investigated. The results indicated that GA3 content was the highest in non\|heading Chinese cabbage seedlings treated under red LED light， in addition， contents of ABA， IAA and ZR were the highest under RB 6∶1 LED. The results of tomato experiment showed that: IAA content was the highest in seedlings cultured under green LED， GA3 content was the highest under blue LED， the contents of ABA and ZR were the highest under RB 6∶1 LED. Different light densities of red plus blue LED light had different effects on growth of tomato seedlings， the result showed that IAA， GA3 and ZR content of leaves were increased with increasing light density， while the content of ABA was inversely proportional to light density.

Key words: LED, non\, heading Chinese cabbage, tomato, endogenous hormone, red plus blue light, light density