Pure zirconium and hafnium metals have opposite applications in the nuclear industry due to their difference in the ability to transmit thermal neutrons. However, the main sources of zirconium, zircon and baddeleyite, are always accompanied by 1-3 wt% of hafnium. Because of their nearly identical chemical properties, separation of zirconium and hafnium becomes the key step in the manufacture of the pure zirconium and hafnium metals for nuclear applications. In order to develop a new separation process, the solvent extraction and separation behavior of Zr(IV) and Hf(IV) has been investigated from sulfuric, chloric, and nitric acid solutions by employing various kinds of extractants and extractant mixture. The characteristics of the extraction in each system was discussed on the basis of the complex formation behavior of Zr(IV) and Hf(IV). Zr(IV) could be selectively extracted over Hf(IV) from strong chloride or nitric acid solutions with cationic extractants following solvation mechanism. On the other hand, selective extraction of Hf(IV) over Zr(IV) was noticed from sulfate medium with cation exchange reaction by cationic extractants. D2EHPA was demonstrated to be the optimum extractant for the selective extraction of Hf(IV) over Zr(IV) from strong sulfuric acid solutions. In comparison with other separation systems, this D2EHPA-H2SO4 separation system is much more pregnant on the development of the separation process, since selective extraction of minor component Hf(IV) over Zr(IV) is always desirable in the aspect of cost. A new process for the selective extraction of Hf(IV) over Zr(IV) from sulfuric acid solutions by using D2EHPA was proposed in present work. In this process, two stripping steps were required to selectively strip Zr(IV) and Hf(IV) from loaded D2EHPA into sulfate and oxalate solutions, respectively. Furthermore, the cross-current batch simulation has been employed to confirmed this process and high purity Zr(IV) and Hf(IV) was successfully attained.