本文针对近年来人们十分关注的石灰性土壤磷的固定问题，对石灰性土壤磷素形态转化、有效性及其与施肥的关系进行了研究。结果表明，石灰性土壤中Ｃａ２－Ｐ是最为有效的磷源，其次分别为Ｃａ８－Ｐ、ＡＬ－Ｐ和Ｆｅ－Ｐ，为缓效磷源，Ｃａ１０－Ｐ和闭蓄态磷则为无效态磷；磷肥施入石灰性土壤后，绝大部分转化为缓效态Ｃａ８－Ｐ，同时有一定量的Ａｌ－Ｐ和Ｆｅ－Ｐ生成，而Ｃａ－Ｐ体系中，基本不存在Ｃａ８－Ｐ进一步向无效态Ｃａ１０－Ｐ转化的现象；同时石灰性土壤磷素形态明显表现出Ａｌ－Ｐ向Ｆｅ－Ｐ的逐渐转化，而Ｆｅ－Ｐ进一步向Ｏ－Ｐ的转化则是极其缓慢的。研究认为，石灰性土壤中缓效态磷基本不存在向无效态磷进一步转化的问题，对于磷在石灰性土壤中的化学行为应有一个新的认识 In this paper, in order to solve the problem of phosphorus fixation in calcareous soil, which is very concerned about in recent years, the relationship between phosphorus transformation and its availability in calcareous soil and fertilization is studied. The results showed that Ca2-P was the most effective phosphorus source in calcareous soil, followed by Ca8-P, AL-P and Fe-P, respectively. Phosphorus; P fertilizer applied to calcareous soil, the vast majority converted to slow Ca8-P, while a certain amount of Al-P and Fe-P generation, and Ca-P system, the basic absence of Ca8-P further to Ineffective state Ca10-P conversion phenomenon; at the same time calcareous soil phosphorus form obviously Al-P to Fe-P transformation gradually, and Fe-P to O-P transformation is extremely slow. It is considered that the slow-acting phosphorus in calcareous soils does not exist any further conversion to ineffective phosphorus and there should be a new understanding of the chemical behavior of phosphorus in calcareous soils