ABSTRACT In this study, Tartarzine aqueous solution was investigated as a simple low-dose dosimeter in the range of 20–500 Gy for the high ionizing radiation, gamma ray. Gradual bleaching of Tartarzine solution was observed with dose by measuring the absorbance of Tartarzine-solutions at specified wavelength, λmax= 430 nm. Tartarzine concentration (10–4, 5 ×10–4 and 10–3 M) and solution-initial pH value (5, 7 and 9) were considered as factors affecting degree of bleaching. It was found that Tartarzine-solution color was diminished gradually with selected dose range. The rate of bleaching increases with the increase of solution-initial pH. Increase of Tartarzine-concentration causes widening of range to which solution is susceptible. The post-irradiated effect (24 hours) was found to cause more bleaching. The sensitivity of Tartarzine solution is not regular with the Tartarzine-concentration and regular with pH.