This study was intended to obtain the basic information on the germination status, changes of $eta$-amylase activity and reducing sugar contents during seed germination of barley after an imposition of water stress by adding Polyethylene glycol solution. The effects of water deficit on germination were to be decreased in germination rate and velocity. Respiratory Quotient was increased as the osmotic potential in culture solution was decreased. But $eta$-amylase activity and reducing sugar contents were decreased and the ratio of dry to fresh weight of germinated seeds was increased as the osmotic potential of the culture solution was decreased.