Objective To establish a qualitative and quantitative determination of glyphosate in serum using ultraviolet spectro-photometry(UV) to provide basis for clinical diagnosing and treating glyphosate poisoning .Methods The mixture of 0 .5 mL serum and 0 .2 mL 10% methanol solution of perchloric acid was shocked and centrifuged with 10 000 r/min for 5 min .A nitrosyla-tion reaction conducted on supernatant and 50 μL serum nitrosylation liquid was detected by UV scanning .Results The results of serum theophylline absorption maxima was(243 ± l) nm and the concentration of 10 .0-60 .0 μg/mL range linear regression equa-tion was Y=0 .0173 8X+0 .036 3(r= 0 .999 8) .The recovery rate was from 85 .5% to 102 .4% and the relative standard deviation (RSD) was from 3 .50% to 4 .90% .The intra-day and inter-day RSD were 3 .79% -5 .10% and 3 .88% -4 .55% .The minimum de-tectable concentration was 5μg/mL .Conclusion This method is simple ,rapid and accurate results for detecting glyphosate poison-ing .