Abstract: The autoregressive spectral estimates of the SMMW Fourier transform spectroscopy data were presented.The modified interferogram was used for the linear prediction with the autoregressive model.Due to the elimination of the "window" effect,the resolution exceeds the value set by the FFT.The procedure of AR spectral estimates and the results were presented.Experimental results show that,this method provides four times higher resolution in the spectrum than the Fourier transform spectrometer does.