Abstract: 【Objective】To study the effects of different LED light qualities on the growth and nutrient accumulation of Tetragonia tetragonoides (Pall.) Kuntze in a plant factory,which could provide a reference basis for the selection of the optimal light quality suitable for the growth and high-quality and efficient cultivation of T.tetragonoides.【Method】Using T.tetragonoides planted in a plant factory as experimental material,four light condition treatments were set up with white light as control (CK) and different ratios of red and blue light (R2B8,R5B5 and R8B2).Forty-five days after the light treatment,growth indexes such as main root length,plant height,stem diameter,number of leaf,leaf area and water con-tent were determined in T.tetragonoides,and photosynthetic pigments contents and photosynthetic parametersincluding photosynthetic pigment content,net photosynthetic rate(P_n),stomatal conductance(G_s),inter-cellular CO₂ concentration(C_i),and transpiration rate(T_r)and nutritional qualities (including tannins,total flavonoids,total saponins,soluble sugars,vitamin C,soluble proteins and nitrates contents) were determined in T.tetragonoides.The correlation between major agronomic shapes and nutritional indicators was analyzed.【Result】Plant height and primary root length tended to increase with increasing percentage of red light and were ranked as R8B2>R5B5>CK>R2B8.The increase in the proportion of red light significantly contributed to the increase in leaf area of T.tetragonoides,and stem diameter,number of leaf,leaf area and fresh weight of T.tetragonoides under R8B2 treatment were the highest,which were significantly increased by30.40%,16.00%,39.14%,and 5.86%respectively compared to that of CK (P<0.05,the same below).In addition,chlorophyll a and total chlorophyll contents were the most abundant under R8B2 treatment,which significantly increased by20.94%and 27.42%respectively compared with CK.The highest P_n was recorded under R8B2 treatment in T.tetragonoides with a significant increase of 59.45%compared to CK;R5B5 treatment reached the minimum P_n.Besides,R2B8 treatment had the highest total saponin content,which was significantly increased by 14.63%compared with CK.The soluble sugar and vitamin C contents showed a trend of increasing and then decreasing with the increase of red light ratio,which peaked and then decreased at R5B5 and R2B8 respectively.Although soluble protein content did not differ significantly among treatments(P>0.05),nitrate content decreased with increasing percentage of red light.Correlation analysis indicated that the growth characteristics and nutrient changes of T.tetragonoides under different LED light quality treatments were closely related.Plant height was extremely significantly significantly positively and correlated with stem diameter,leaf area and fresh weight (P<0.01,the same below),and P_n was extremely significantly and positively correlated with chlorophyll a,total chlorophyll contents,and stem diameter in T.tetragonoides.Total flavonoids were significantly and positively correlated with tannins and soluble proteins,and nitrate was negatively correlated with stem diameter,chlorophyll b and G_s.【Conclusion】Different ratios of red and blue lights affect the growth and nutrient accumulation of T.tetragonoides in a plant factory.When the ratio of the two light qualities is R8B2,it can promote photosynthesis,morphogenesis and nutrient accumulation,reduce the nitrate content and improve the edible taste,which can be applied in actural planting of T.tetragonoides.