Herein, we develop a reproducible in situ crystallization route to synthesize uniform functional ZSM-5 microspheres composed of aggregated ZSM-5 nanorods and well-dispersed uniform Fe(3)O(4) nanoparticles (NPs). The growth of such unique microspheres undergoes a NP-assisted recrystallization process from surface to core. The obtained magnetic ZSM-5 microspheres possess a uniform size (6-9 μm), ultrafine uniform Fe(3)O(4) NPs (~10 nm), good structural stability, high surface area (340 m(2)/g), and large magnetization (~8.6 emu/g) and exhibit a potential application in Fischer-Tropsch synthesis.