Abstract: Experimental curves of magneto-impedance for LCN（a LC-circuit contained Fe-based nanocrystalline ribbon）and for LN（a coil contained Fe-based nanocrystalline ribbon）were presented.The curves for LCN were compared with those for LN.It is found that, the mag neto-impedanceratio（△Z/Z₀） of LCN ishigher than that of LN, the li near range of △Z/Z₀ changed is larger for LCN than for LN.In addition,the reare ch aracteristic frequenciesin the cur ves of magneto-impedance for LCN.According to the characteristic frequencies f_r0,f_rhmax, f_r, the formation of curves of magneto-impedance for LCN can bededuced,and the magnetic sensitivity of LCN, the linear range of △Z/Z₀ changed can be controlled effectively.