Abstract: The method for determination of components of the compound tablets of phenobarbital, phenacetin, amidopyrine and caffeine(PPAC) by HPLC is developed. The experiment was carried out under the following conditions: column, YWG-CH 200*5mm(I.D.)；mobile phase, a 50% solution of methanol in 0.002M K_2HPO_4 adjusted to pH 8.0 by H_3PO_4；column temperature, 22℃；pressure 120kg/cm2, flow rate,1.0ml/min. The components were monitored by a spectrophotometric detector at 254nm and acetanilide was used as an internal atandard. Under the above mentioned conditions, the four components in the compound tablets could be separated and determined satisfactorily. The method was simple, rapid and accurate. The recoveries of PPAC were 97.9%, 100.6%, 100.2%, 100.0% respectively.