A piezoelectric/electrostrictive porcelain composition which exhibits superior piezoelectric/electrostrictive characteristics without containing lead (Pb) is provided. A main component of the piezoelectric/electrostrictive composition is a binary solid solution represented by the general formula (1): (1-n)(Ag.sub.1-a-b-cLi.sub.aNa.sub.bK.sub.c)(Nb.sub.1-x-y-zTa.sub.xSb.sub- .yV.sub.z)O.sub.3+nM.sup.1M.sup.2O.sub.3; wherein 0.ltoreq.a.ltoreq.0.2, 0.ltoreq.b.ltoreq.0.95, 0.ltoreq.c.ltoreq.0.95, 0<(1-a-b -c).ltoreq.1, 0.ltoreq.x.ltoreq.0.5, 0.ltoreq.y.ltoreq.0.2, 0.ltoreq.z.ltoreq.0.2, 0.ltoreq.(y+z).ltoreq.0.3, 0.ltoreq.n.ltoreq.0.2, and wherein M.sup.1 and M.sup.2 are combinations of metal which satisfy pretermined conditions.