Objective：To prepare superparamagnetic Fe3O4 chitosan nanoparticle and to explore the effects of different surfactants and crosslinkers on prepared nanoparticles. Methods：The nanoparticle was prepared by chemical co-precipitation method. The size，poly－dispersity index and zeta potential was detected by Zetasizer Nano. The magnetization intensity was detected by vibration sample magnetometer. Results：The size of the nanoparticle ranged from 15 nm to 60 nm，with an average size of 29.39 nm. Polydispersity in－dex was 0.185 and the absolute value of zeta potential of the nanoparticle was approximately 20. Magnetic induction was very well. Conclusion：The surfactants with low hydrophile lipophilic balance value can reduce the size of nanoparticle. Glutaraldehyde dosage should be controlled between 1.5 ml and 2.0 ml. Concentration of NaOH solution should be controlled between 3.0 mol/L and 4.0 mol/L.