Abstract: Three calcareous soils were taken to investigate the effect of salt concentration and organic matter on their exchange selectivity coefficients. In homovalent exchange (K+-Na+) all the three soils showed an increase in the values of selectivity coefficient with increasing salt concentration and organic matter. The maximum value of Kk was observed at 4.00% level of organic matter and 2:1 salt concentration. In case of heterovalent exchange (K+-Ca2+) there was also an increasing trend in Kerr (Kk) Vanselow (Kv) and Gapons (KG) selectivity coefficients values with the increase in salt concentration and organic matter. Moreover the results indicated preferential adsorption of K+ over Na+ in case of homovalent exchange and Ca2+ over K+ in case of heterovalent exchange.