Abstract: The usual non-volatile poisons are divided into 3 groups and treated respecti- vely by ascending chromatographic method for the acidic organic poisons, by descending chromatographic method for the basic organic poisons, and Giri's method for metallic poisons, all using Whatman No. 1 filter paper. For the acidic poisons, we have separated phenacetin, salicylic acid, barbital and phenobarbital on paper treated with 3. 5% KCl, using n-octanol: ammonium hydroxide (sp. gr. 0. 88) : water=100: 7.5:100, n-octanol: cyclohexanol: ammonium hydroxide: water = 50: 50: 7.5: 100 and n-octanol: cyclohexanol: ammonium hyd- roxide: water=25: 75: 7.5: 100, as the developing solvents, with the best results ever obtained. The R_f values and visualizing reagents are listed in Tab. 1. The relations between R_f values and the proportions of n-octanol to isoamyl alcohol and of n-octanol to cyclohexanol are shown in Fig. 1, 2. For the basic organic poisons, by 7 methods prominently selected, we have got favorable results (Fig 4) using filter paper treated by acidic salts, with n- butanol and isoamyl alcohol as the solvents. The R_f values obtained by the above methods are shown in Tab. 2. Of all the 7 methods, the one using filter paper, treated by sodium dihydrogen citrate, with n-butanol: isoamyl alcohol: hydrochloric acid: water=10: 10: 2: 40 as the solvent, is considered to be the best in respect of separating 8 compounds from one another in this group. The relation between R_f values and proportions of n-butanol to isoamyl alcohol are manifested in Fig. 3. The temperature affects the R_f values and with the increase of the temperature, the R_f values of 5 out of 8 compounds increase while those of the rest, on the contrary, decrease, as shown in Fig. 6. The basic dissociation constant is one of the factors to affect R_f values in this group. For the metallic poisons, the mixture of HCl of different corcertrations with absolute alcohol as developing solvents are used and the relation of HCl of various concentrations with R, (R_fc) is shown in Fig.5. A good result from 3 N HCl: absolute alcohol =1:9 and the best result ever produced from 5 N HCl instead are shown by their R_r values in Tab. 3. In addition, we have tested pheracetin, barbital, pherobarbital, chromium and arsenic on filter paper by new or modified methods, with satisfaction.