Callus derived from mature seed scutella of Oryza sativa L. cv. Taipei 309 was initiated on LS medium (Linsmaier and Skoog, 1965) semisolidified with 0.4% (w/v) Sea Kern agarose (Flowgen Ltd., Shenstone, UK) and supplemented with 2.5 mg 1~ ’ 2,4-dichlorophenoxyacetic acid (2,4-D). This callus was used to initiate cell suspensions which were maintained by sub-culture every 7 d in The protoplast plating efficiency of this, and other economically-important cereals, is still low when compared to the generally more efficient protoplast systems of their dicotyledonous counterparts. Abdullah et al. (1986) reported that while initial division occurred in up to 57% of cells derived from cultured protoplasts isolated from several varieties of Japonica rice, only ca. 1% of such protoplasts underwent sustained mitotic division leading to visible cell colonies. The results obtained using rice protoplasts are dependant on a number of variables, primarily the source material and plant genotype. At present, embryogenic cell suspensions are the prime source material for the isolation of totipotent rice protoplasts. How- ever, as well as the choice of plant variety, source material and culture medium used, additional innovative approaches are also required to elevate rice protoplast systems, in terms of their plating efficiency, to levels more comparable to those of dicotyledons.