Abstract: Three pulsars (PSR 0329+54,0834+06,1133+16) with high quality signal-to-noise of radio mean pulse profiles are selected from the available literature.The characteristics of the radio mean pulse profiles are analyzed for three pulsars.The phase-resolved spectrum and the correlations between radio emissions flux and frequency at the same phase are obtained.The results are as follows: The characteristics of the phase-resolved spectra are different among three pulsars.For 1133+16,the spectra is steep at two sides of pulse profiles,otherwise flatter in the middle.For 0329+54 and 0834+06,the spectra are flat at the leading part and steeper at the trailing.According to those spectra characteristics,pulsars can be classified.For 1133+16,there are good correlations between radio emission and frequency at same phase,and when |Φ| > 3°,the correlation coefficient R>0.8 and chance probability P<0.03,which show that the radio emission of 1133+16 is power low spectrum.So,for 0329+54,when 4° > Φ > 3°  and Φ < -3°,R>0.5,P<20%,and for 0834+06,those relationships are mutative and weakly at different phase,and means the radio emission may be not power low.

Key words: radio pulsars, mean pulse profiles, phase-resolved spectrum