Abstract:The field sampling and laboratory analysis were conducted to study the content changes of iron Forms and their profile variations in current paddy soils and ancient paddy soils at Sanlonggang village of Liyang plain. The relationship between the changes of iron forms and soil forming process was analyzed. The results showed that the contents of different iron forms in current and ancient paddy soils in Liyang plain are: total iron was by 31.61-35.10 g/kg and 33.97-46.88 g/kg; free iron 8.88-13.92g/kg and 11.10-20.36g/kg; amorphous iron 2.52-4.06g/kg and 2.64-3.35g/kg; Crystal iron5.06-11.40g/kg and 8.46-17.43g/kg, respectively. Apart from amorphous iron, the iron concentration changed dramatically with the trend of ancient paddy soils > current paddy soils in Liyang plain soils, and the obvious variation of the different form The field sampling and laboratory analysis were conducted to study the content changes of iron forms and their profile variations in current paddy soils and buried ancient paddy soils at Sanlonggang Village of Liyang Plain. The relationship between the changes of iron forms and soil forming process were also analyzed. The results showed that the contents of different iron forms in current and buried ancient paddy soils in Liyang Plain were: total iron 31.61–35.10 g/kg and 33.97–46.88 g/kg; free iron 8.88–13.92g/kg and 11.10–20.36g/kg; amorphous iron 2.52–4.06 g/kg and 2.64-3.35g/kg; crystal iron 5.06–11.40g/kg and 8.46–17.43g/kg, respectively. Except amorphous iron, the concentrations of other iron forms changed in the trend of ancient paddy soils > current paddy soils. Obvious variations of different iron forms were observed in buried ancient paddy soils. For the current paddy soil, the contents of total iron, free iron and crystal iron increased with increasing depth, the opposite trend was found for amorphous iron, and the variations of different iron forms in the profile changed less. For buried ancient paddy soils, the content of total iron increased with increasing depth while amorphous iron increased slightly, the contents of free iron and crystal iron decreased in PA profile but increased in PC profile. The change modes of the different iron forms were diverse in the buried ancient paddy soils, obvious iron eluviation and deposition process were existed in the ancient paddy soils, the contents of different iron forms changed significantly in different horizons and the iron enrichment were obviously the buried ancient paddy soils.