La, Ce, Pr, Nd, Sm, and Eu elements were used in order to determine variation of K β to Kα X-ray intensity ratios at the magnetic field (B= 0, 0.4, 0.8 T). The samples were irritated by 59.54 keV γ-rays from 241 Am radioactive point source via energy dispersive X-ray fluorescence spectroscopy. K X-rays emitted by samples were counted with a high resolution Si(Li) solid-state detector. The experimental results were compared with the literature. The analysis shows that K β to Kα X-ray intensity ratios of the elements without magnetic field are compatible with the past studies and although K β and Kα peak intensities change with variation of the magnetic field, the intensity ratios do not change.