Abstract: Objective To study the security and health care of water of frequency spectrum.Methods The tests were done according to "Procedures and methods for toxicological assessment on food safety","Detecting method and functional evaluating process for health food".Results The LD₅₀ is>15 000mg/kg(oral to NIH mice) belong to no-toxic level.The micronucleus test of bone marrow cell,the test of sperm shape abnormality in mice,Ames' test and ninety days feeding test have not significant difference on toxicity compared with the control group (P>0.05 ).Mφ percentage of phagocytosis and the content of serum lysozyme increase significantly compared with the contorl group(P≤0.01),but anti-fatigue test and the ratio of T-lymphocyte transformation do not have significant difference compared with the control group(P>0.05).Conclusion The water of frequency spectrum is security and no-toxic.It may be able to improve immunity function of human beines.