Abstract:Calli were induced from anther protoplasts in suspension cultures, and from mature embryo derived callus. After transferring the calli into plant differentiation medium, plantles were obtained. The protoplast plating efficiency and plantlet regeneration frequency were influenced not only by rice (Oryza sativa L.) genotypes but also by the age of suspension lines. The F2 anther-derived calli gave a protoplast plating efficiency of 4.5 %–9.6 % and plantlet regeneration frequency of 20.0 %--36.7 % using agarose-imbedded method. In comparative study of the agarose-imbedded culture and nurse culture, the latter method seemed to be more advantageous in time saving and high efficiency.