Weierning tablet is a new Chinese traditional patent medicine. Its main ingredients Codonopsis pilosula, Magnolia officinalis and Strychnos nux-vomica were identified by TLC. An HPLC method for the determina tion of strychnos and brucine was established. The method is sensitive and highly reproducible. Its average re covery were 99. 24% and 98. 39% respectively;RSD=1. 61 % for strychnos,and 1. 80% for brucine (n=3)