Abstract: To further explore the molecular mechanism of LF-EMF at protein and metabolism levels,the proteomic analysis of Saccharomyces cerevisiae irradiated by 50 Hz LF-EMF were determined by SWATH-MASS. The differentially expressed proteins were matched with Unitprot database,and the metabolic pathways of differentially expressed proteins were analyzed. The results showed that 50 Hz LF-EMF could significantly affect the expression level of 12 kinds of proteins in Saccharomyces cerevisiae(P<0.05),including 3 up-regulated proteins(↑15.78%~34.21%)and 9 down-regulated proteins(↓14.43%~40.59%). The up-regulated proteins were mainly concentrated in the pathway of free radical metabolism,carbon metabolism,amino acid biosynthesis and glycerolipid metabolism,while the down-regulated proteins were mainly enriched in the pathway of inositol phosphate metabolism,nitrogen metabolism,glutathione metabolism,pyrimidine metabolism,purine metabolism and antibiotic biosynthesis. In addition,the differentially expressed proteins(such as inositol triphosphate synthase)would also affect the production of its related metabolites(such as inositol triphosphate)significantly(P<0.05). Therefore,LF-EMF radiation could affect the expression level of proteins and the metabolic level of its related products in S. cerevisiae.