The spectral interferences of La, Tb, Ho and Er (1,000 micrograms.mL-1, separately) as matrices on the other rare earth elements (REEs, 1 or 5 micrograms.mL-1) were studied with a high resolution ICP atomic emission spectrometer with a grating of 3,600 grooves/mm. Totally 66 analytical lines of 15 REEs were selected as the prominent lines in the spectral interference studies. The overlapping profiles of analytical lines and interference line were obtained by scanning different solutions (blank, analyte, and four REE matrices, individually) within the selected wavelength windows (0.2 nm for each analytical line). Some new spectral lines of La, Tb, Ho and Er were observed. The "best" analytical lines of 14 REEs were recommended based on the Q-values and the true detection limits.