Abstract: Spinel lithium zinc ferrite(Li_0.35Zn_0.3Fe_2.35O₄) was prepared by a sol-gel method, which was composed with polyaniline by an interfacial polymerization method. FT-IR, XRD, SEM and vector network analyzer (VAN) were used to investigate chemical composition, micro-morphology, electromagnetic property and microwave absorbing property of the composite. The results show that polyaniline fibers are grafted on the surface of Li_0.35Zn_0.3Fe_2.35O₄ particles to form dendritic structure. The length to diameter ratio reaches maximum when PANI fibers are doped by hydrochloric acid (HCl) （diameter 75~90 nm,length 710~800 nm）. Absorption bandwidth with reflection loss value <-10 dB is up to 4.1 GHz and the maximum microwave decay value is -20.5 dB at 3.9 GHz and -33.1 dB at 15.8 GHz. The dendritic composite exhibits excellent microwave absorbing capacity.