The present experiment comprised two parts to study solubility of some macro-elements( Na, K, Ca and P) and some micro-elements ( Zn and Cu )  from some common Egyptian  feedstuffs, berseem hay rice straw concentrate feed mixture and barley grains. In part one the feedstuffs were soaked in water for 15 minutes to determine mineral solubility. In Part two, feedstuffs were incubated for 72 hours in rumen of fistulated Barki sheep fed different roughage to concentrate ratios (70:30, 50:50, and 30:70). \ Results showed the  following: Soaking feedstuffs in water  had a significant effect on the DM disappearance and minerals solubility . Sodium and potassium were the highest soluble among the macro-elements, while copper was more soluble than zinc.  Although there was no significant difference in solubility of most minerals among feedstuffs incubated in the rumen of sheep fed diets of  different R/C ratios, zinc solubility tended to increase in high roughage diet.  There was significant difference in rumen fluid pH among  experimental treatments. The VFA^,s were higher in high concentrate diets ( and the difference was significant at 6 hours ). Moreover NH_3-N concentration was not significantly different among diets, and tended to increase in high concentrate diet.     It could  be concluded that, solubility of minerals may be  affected by kind of element, fiber constituents of feedstuffs and rumen fluid pH.