Considering the interaction between carbon nanotubes(CNTs) and ferromagnetic particles filled in CNTs, develops a modified model based on Aharoni exchange resonance model. Uses the model to simulate the carbon nanotubes filled respectively with iron, cobalt and nickel, and calculates their exchange resonance frequency in the frequency of 2～18 GHz. The computed results, which Fe-filled CNTs is 15.586 GHz, Co-filled CNTs is 15.643 GHz and Ni-filled CNTs is 13.175 GHz, are consistent with experimental data.