Abstract: On a partition chromatographic column in which the support is Kieselguhr and the stationary phase is sulfuric acid solution (2 mol/L), three components of compound theophylline tablet were simultaneously eluted by chloroform and three other components were simultaneously eluted by ammonia--saturated chloroform. The two mixtures were determined by computer--aided convolution curve method separately.The corresponding average recovery and relative standard deviation of the six components were as follows: 101.6, 1.46% for caffeine; 99.7, 0.10% for phenacetin; 100.9, 1.31% for phenobarbitone; 100. 2, 0.81% for theophylline; 99.9, 0.81% for theobromine and 100. 8, 0.48% for aminopyrine.