Abstract: In view of the environmental pollution from mercury in determination of iron by means of stannous chloridemercury chloridepotassium dichromate titration, a new method without use of mercury reagent is proposed in this paper. By cutting off air, aluminium tablet is used to reduce ferric to ferrous and then ferrous is determined by potassium dichromate titrimetry. The method is reliable with precision of 0.61%RSD(n=5) and suitable for the determination of iron in pyrites.