Voltammetric behaviour of 1-Methylguanosine(1-MG) has been investigated at Glassy Carbon Electrode(GCE) by cyclic voltammetry(CV), linear sweep voltammetry(LSV), differential pulse voltammetry(DPV), square ware voltammetry(SWV). In the Britton-Robinson(pH2.0) buffer solution, one well-defined oxidation peak of 1-MG is proportional to the concentration of 1-MG over the range of 4.0×10~(-7)~1.0×10~(-5) mol/L.The detection limit is 6.6×10~(-8) mol/L. This method was successfully applied to the analysis of urine samples and serum sample with recoveries 96.0%~102.0%.