Spherical nanoparticles of superparamagnetic akaganeite (beta-FeOOH) without aggregation are prepared by the inducing role of ethyl acetate under 373 K during 10 min. The X-ray diffraction and IR spectra displayed the crystalline nature of beta-FeOOH structures. Transmission electron micrograph of the samples revealed that the average diameter of nanoparticles with good dispersity is 14.7 nm. The measurements by superconducting quantum interference device (SQUID) magnetometry showed that the samples is the superparamagnetic above the blocking temperature of 18 K under field cooling.