Abstract: An investigation was made on the initiation, maintenance and regeneration of callus from mature seeds as explants of eight rice cultivars, viz., Khitish, IR 64, IR 36, IR 72, PNR 546, Swarna, Taraori Basmati and Gobindabhog. Mature seeds were used as explants. MS medium supplemented with 2mgL-1 of 2, 4-D was found suitable for inducing high amount of embryogeniccalli in the studied genotypes. In this hormonal concentration, maximum 95% callus was induced in IR 64, followed by 91.6% in PNR 546. Maximum root - shoot induction (67%) was also observed in the same media component in IR 64. IR 64 was found most suitable for in vitro culture among these genotypes used. Plants regenerated in vitro were successfully established in soil. However among the genotypes studied IR 64 was rated as good and PNR 546 moderate in respect to regeneration capability. Media 5 (2, 4 D and BAP 2mg/l) and 6 ( NAA and BAP2.50 and .050 mg/l) were selected for callusing. However media 5 showed better regeneration potential.