Plant nutrient is an important factor that affects the growth of Astragalus membranaceus.The effects of N，P and K on the growth and medicinal components of Astragalus membranaceus were studied in order to provide basic support for the nutritional regulation of Astragalus membranaceus in cold region.Through the N，P and K single factor field experiment and L9(34)orthogonal test，the apparent plant growth and medicinal ingredients of annual Astragalus membranaceus in different nutrient levels and multiple factors were analyzed.1)The plant heights of Astragalus membranaceus with different nitrogen levels had no significant difference.The root length of N2 was significantly higher than other levels(P<0.05).The difference of stem diameter，root diameter at 10 cm(R1)of N2 and N3 was not significant，but significantly higher than that of N1 and CK.There was no significant difference in underground fresh weight under nitrogen treatments(P> 0.05)，and there was no significant difference in aboveground fresh weight between N3 and N1，N3 and N2，but it was significantly higher than CK(P<0.05).The campanulin and the ononin of N2 were not significantly different from N1 and N3，but significantly higher than CK(P<0.05).The calycosin among different levels was not significant.The difference of polysaccharide between N2 and N1 was not significant，but was significant with N3 and CK.Under different phosphorus levels，the root length of Astragalus membranaceus showed no significant difference between P3 and P2，but was significantly higher than that of P1 and CK(P<0.05)；there was no significant difference in root diameter at 10 cm(R1)between P1 and P2，but was significant higher than that of P3 and CK(P<0.05).The P1 treatment of Astragalus membranaceus roots had the highest content of isoflavone glycosides and formononetin in the root system(P<0.05)，while the content of polysaccharides was significantly lower than other treatments.Under different potassium levels，the plant height，root diameter at 1 cm(R0)，underground fresh weight，and the above ground/underground fresh weight ratio of K2，K3 and CK were not significantly different，but significantly higher than those of K1(P<0.05).The contents of the campanulin and the ononin of K2 were not significantly different with K1 and CK，but significantly higher than K3(P<0.05).The content of the calycosin of K3 was significantly higher than other treatments.The polysaccharide content was significantly different，and the order of content was CK>K3>K2>K1. 2)Under the mix application of N，P and K，the plant height，the stem diameter，the root diameter(R1)，aboveground fresh weight and belowground fresh weight were significantly affected by K element(P<0.05)，while N and P had a less effect on Astragalus membranaceus.The campanulin and polysaccharides were significantly affected by N，P and K elements(P <0.05)，and the influence order was K>N>P，and the ononin was significantly affected by N and K elements(P <0.05).There was no significant difference in the content of the calycosin in different treatments.the application of nitrogen and potassium was beneficial for plant growth，biomass and polysaccharide accumulation.The effect of nitrogen，phosphorus and potassium on Astragalus membranaceus was K>N>P. The N2，P2 and K2 promoted the growth of Astragalus membranaceus significantly under the sigle element fertilization，while N2，P1 and K2 promoted accumulation of the medicinal components significantly.When the three elements were applied together，the treatment of N2P2K3(N 20 g/m2，P 15 g/m2，K 30 g/m2)was beneficial to the growth and the accumulation of roots polysaccharides of Astragalus membranaceus.The treatment of N1P2K2(N 10 g/m2，P 15 g/m2，K 20 g/m2)was beneficial to the accumulation of flavonoids.It is suggested that directional fertilization management should be carried out according to production needs.