L i (i=1, 2 and 3) X-ray fluorescence cross sections for Ta, W, Au, Hg, Tl, Pb, Bi, Th and U have been measured using the 59.54keV incident photons energy in the external magnetic field of intensity +0.60T. The values of L i subshell fluorescence yields (w1, w2 and w3) have been measured for the same elements using the previously measured cross section values and the theoretical L i subshell photoionisation cross sections, Coster–Kronig transition probabilities and emission rates. It is observed that the measured L i subshell X-ray fluorescence cross section and L i subshell fluorescence yield values for B=0 are in good agreement with the theoretical ones evaluated using L i subshell fluorescence yield and L i subshell photoionization cross section. Furthermore, the results show that the atomic parameters such as spectral linewidth, radiation rates, photoionization cross section and fluorescence yield can change when the irradiation is conducted in a magnetic field.