This paper presents the harmonics and interharmonics analysis of a passive magnetic fault current limiter (MFCL). This device limits the current at post fault without affecting the pre fault state of the system. The harmonics and interharmonics estimation of a non-stationary signal generated by MFCL has been investigated using Morlet Wavelet transform and FFT. Continous wavelet transform (CWT) have been applied for estimation of harmonics and interharmonics in MFCL under normal and faulted condition.