A high performance liquid chromatographic (HPLC) method was established to determine the Huperzine A in the extract of Huperzia serrata. After extracted by methanol/ water/formic acid (10/90/0.2, v/v/v), the sample was filtered for HPLC analysis. The separation was performed on an XCharge C18 column (150 mm x 4.6 mm, 5 microm) by gradient elution with water (containing 0.1% (v/v) trifluoroacetic acid) and acetonitrile (containing 0.09% (v/v) trifluoroacetic acid) as the mobile phases. Rapid separation was achieved within 10 min at a flow rate of 2 mL/min with ultraviolet absorption detection at a wavelength of 310 nm. Under the optimized conditions, good linearity was obtained in the range of 2. 12 - 106 mg/L with the correlation coefficient (R2) of about 0.999 9. The average recovery was 102.34% with the relative standard deviation (RSD) of 0.46%. The intraday and interday precisions were all below 2%. The results demonstrate that this method is simple, rapid and accurate with good reproducibility, and can be used to evaluate the quality of Huperzia serrata.