${eta}-$Ag_2S$(high temperature phase) was grown by solid/vapour reaction growth based on solid -state electrochemisty. In S/V growth, one of the reactants, silver ion, is supplied to the growth surface through the solid $Ag_2S$ from one side and the other reactants, surfur, is transported in the phase of vapour from the other side. With the sufficient supply of S vapour, the growth rate increased as increasing $T_d$(decomposition temperature of $Ag_2S$) and ${Delta}T$ between $T_d$ and $T_g$(temperature of growth surface). At low S vapour pressure, growth rate decreased with decreased vapour pressure and ${eta}-$Ag_2S$</TEX> was grown in the form of whisker, when Ag+ion is sufficiently supplied. The measured values of electronic conductivity of ${eta}-$Ag_2S$ showed that electronic conductivity of the poly crystal was larger than that of single crystal.