Abstract: A new method for estimation of strychnine salts is proposed as follows:pipet accurately 10 ml of M/80 K₂Hgl₄ solution into a 50 ml volumetric flask.Add 5 drops of sodium bisulfite solution.After shaking,add precisely a measureod volume of sample solutions(equivalent to about 30 mg of strychnine salt)and 2ml of hydrochloric acid solution.Shake for 1 minute and then allow to stand for 15 minutes.Filter through a dry filter paper,discard the first 10 ml of filtrate and pipet 25 ml of the subsequent filtrate into 250 ml Erlenmeyer flask.Add 5 ml of 10% potassium chloride solution 6 ml of 5% potasssium chlorate solution,3 ml of concentrated hydrochloric acid solution and 30 ml of distilled water,and boil until the solution is colorless and transparent(about 1—3 minutes).Cool to room temperature. Add 70 ml of distilled water,3 drops of phenol solution and 2 drops of methyl red indicator(more phenol solution may be added if the solution is decolorized).Neutralise with 10% NaOH solution and then readjust to pink color by careful addition of 2N HCl solution.Add 20 ml of NH₃-NH₄Cl buffer solution,2 ml of Eriochrome Black T indicator and 2 ml of methyl red indicator.Titrate with M/400 EDTA.2Na.Mg solution on a titrating apparatus in port of artificial light sources until color changes from olive green→brown→red→brown→green.A blank is made accordingly. The method described above is simple,rapid and accurate which is suitable for estimating strychnine salts as well as its simple preparations.The accuracy of this method is within ±0.2% in comparison with the official method.