In this paper, we fabricated crystalline FePO₄ microstructures with controlled morphologies at relatively low temperature through kinetic manipulation. The morphology evolution was directly observed during the experiments. The morphologies were mainly determined by the amount of the H₃PO₄ in the reaction system. The morphologies of the obtained FePO₄ changed from rugby to porous microsphere through controlling the concentration of the H₃PO₄. During the growth of the final porous microspheres, we observed some interesting processes which revealed the special configuration of FePO₄ micro/nanostructures. The rational growth mechanism of the FePO₄ microstructures was discussed in detail, which was significant not only for researching the properties of iron(III) phosphate, but was also important to understand the kinetic process of crystal growth and guide the synthesis of other crystalline materials.