Abstract:Protoplasts isolated from 3--4 day-old (ca 4 cm in length) etiolated hypocotyls of Brassica carnpestris var. parachinesis (Bally) Tsen et Lee and purified with 20% sucrose were cultured on K8p medium suplemented with 0. 5 mg/L ZT, 0.5 mg/L 2, 4-D, 1.0 mg/L NAA and 0. 4 mol/L glucose. When initially cultured for 14-18 hours the protoplasts formed new walls and by first division after 36 hours. The divided protoplasts reached 35 % after being cultured for three days. When cultured under optimum conditions for 8-9 days, the proto plasts formed 8-16 cell colonies with a plate effeciency as high as 15%-18%. Rapidly growing and dividing calli of 2 mm in diameter were transferred onto semisold gelrite media with 0.3 mg/L 2, 4-D enabling them to proliferate further towards the size of 4-5 mm in diameter. Shoot differentiation was carried out in MS medium with 3.2 (or 1.6) mg/L BA, 1.6 (or 0.8) mg/L ZT, 0.01 mg/L NAA, 0. 1 mg/L GA3 and 0.2 % sucrose. Shoots were cut down and rooted on medium with 0.2 mg/L IAA and 2 % sucrose where whole plants were evatually developed.