Based on the numerical solution of the lidar equation the feasibility for sounding of iodine isotopes in the atmosphere using the fluorescence method has been studied. As a fluorescence excitation source the Nd-YAG laser second harmonic generation is taken; the variants of sensing by other laser sources are analyzed. The minimum detectable value of iodine concentration for remote sensing at distances from 0.5 to 10 km is 1010 cm-3 at peak power of a sounding pulse of 10 MW.