Two important aspects of in vitro studies on germination and plant regeneration of Impatiens platypetala Lindl. were investigated. In the first study, factors affecting in vitro germination of immature ovules were investigated. In the second study, factors affecting in vitro plant regeneration from cotyledonary explants were investigated;Several carbohydrates inhibited in vitro germination of immature ovules. Germination was inhibited by sucrose or mannitol at 0.05 M, whereas inhibition did not occur until the concentration of glucose was raised to 0.1 M. The percent of germination increased with increasing explant age from 12 to 16 days old. Abnormal seedlings developed at total nitrogen concentrations higher and lower than 30 mM;Organogenic tissues from cotyledonary explants were successfully induced on organogenic tissue induction (OTI) medium. Both NAA and BA were essential for OTI. Glutamine at 500 mg/liter enhanced the OTI response. OTI was also affected by explant type and age. An average of 7.6 shoots per explant were regenerated on shoot induction medium, and shoots were successfully rooted in a basal MS medium containing 30 g/liter sucrose.