A new mode for the FIA method was developed for the estimation of Chlorpromazine HCl(CPH) in pure and pharmaceutical formulation based on the releasing of the oxidizing agent sodium persulphate from the body the hydrogel beads leads to oxidation of drug to pink color product. Homemade FI photometer, single hydrogel bead and green light emitting diod were used for this application. The optimum conditions were 1ml.min-1 flow rate, 100μL injected sample volume, 15sec as purge time of injected sample volume, 0.5mol.L-1 of sodium persulphate that gel bead soaked in and 3hours of soaking time for hydrogel bead inside sodium persulphate solution. The linear range for the variation of instrument response with CPH concentrations was 0.17-0.80mmol.L-1, While the limit of detection (L.O.D) was 0.108x10-8M from the stepwise dilution of the minimum concentration in the linear range. The correlation coefficient(r) was 0.9945. The method was applied successfully for the determination of CPH in pharmaceutical preparation, and paired t-test indicate that there was no significant differences between the new method and the reported method , so on that base the new method can be used as an alternative analytical method.