Coster-Kronig processes are radiationless in which an inner-shell vacancy is transferred from one subshell of an atom to another, both belonging to the same principal shell. Because of the effect of Coster-Kronig transition on L X-ray fluorescence cross sections, an increase in L X-ray intensity were calculated theoretically at different exciation energies for L-1, L-2 and L-3 subshells. These are called as Coster-Kronig enhancement factors and were represented as K-i(i = alpha, beta, l). These calculated values were compared with other experimental and theoretical values. Calculations showed that when the excitation energies were increased with respect to absorbtion edge energy, L X-ray fluorescence cross sections decrease while Coster-Kronig enhancement factors increase.