Abstract: The GCE was placed in 1.0 mol·L-1 NaOH solution and scanned in the potential range of 0.5-1.5 V (vs.Ag/AgCl) at the rate of 100 mV·s-1 by CV to prepare strong alkali activated GCE. As shown by the result of DPASV study, in a B-R buffer solution of pH 3.0, oxidation peaks of acyclovir and famciclovir were observed at the potentials of 1.08 V and 1.28 V. Linear relationships between values of concentration and peak current of the 2 drugs were kept in the ranges of 4.2×10-6-8.5×10-5 and 2.0×10-6-6.5×10-5mol·L-1 with detection limits (3S/N) of 4.0×10-7mol·L-1 and 3.5×10-7mol·L-1 respectively. The proposed method was applied to the analysis of protein free serum sample, and tests for recovery were made by standard addition method, giving values of recovery in the ranges of 94.0%-98.8% and 94.3%-120%, with of RSD′s (n=8) in the range of 0.6%-2.1% and 1.2%-1.9% respectively.