Shredded (grain size 125-250 mu m) Ca sorbents unmodified or modified sep. with Na or Li compds. with the content of each additive in the range of 0.5-1.5% by mass were used for desulfurization of N-2 contg. SO2 (1870 ppm) and O-2 (3%). Reactivities of the tested sorbents were detd. The addn. of Na2CO3 in quantities of 1% and 0.5% to the sorbent resulted in a decrease of the reactivity coeff. by 14.3% and 15.3%, resp. The sorbents modified with the Li compds. were more reactive.