In the present study we investigated the morpho-physiological and biochemical responses of microсlonally produced seedlings of Paulownia Pao Tong Z07 under exposure to silver nitrate (AgNO3 ) in various concentrations (1, 10, 50 mg L-1) in the growth media. The exposure to AgNO3 at all studied concentrations resulted in a significant enhancement in seedling growth, as evidenced by notable increments in shoot length, stem mass and leaf mass. Seedlings treated with AgNO3 showed higher catalase activities, ascorbate peroxidase, and ascorbate oxidase. At the same time, the activities of superoxide dismutase and glutathione S-transferase, the concentrations of low molecular mass thiols and carotenoids dropped in plants exposed to AgNO3 . The levels of chlorophylls a and b were unaffected by any silver nitrate concentration. The results suggest that silver nitrate, at concentrations of 10 and 50 mg L-1, has modulating effects on the antioxidant defense of Paulownia.