The effect of different conditions for in vitro proliferation, and soil conditions for sporophyte formation, were studied in Onoclea interrupta (Maxim.) Ching & P. C. Chiu. The gametophytes produced from in vitro-germinated spores were then cultured for eight weeks on Murashige and Skoog (MS) medium at quarter-, half-, full-, and two-fold strength, and full-strength Knop medium. Maximal fresh weight gains (10.2 g) and excellent rhizoid and gametophyte morphogenesis were obtained with full-strength MS medium. The effects of sucrose concentrations (0, 1, 2, 3, 4%) and activated charcoal (0, 0.2, 0.4, 0.8%) in full-strength MS medium, and the effect of different N concentrations (30, 60, and 120 mM) were also studied. Sucrose at 1% led to the highest gametophyte weight (4.2 g). Activated charcoal did not affect weight. Nitrogen with an NH₄⁺ to NO₃^– ratio of 1 : 2 at 30 mM led to good weight gain (3.5 g). Sporophyte formation occurred on all researched soil substrates after 12 weeks. Maximum sporophyte production (405 sporophytes) occurred in mixed soil containing horticultural substrate and decomposed granite in a ratio of 2 : 1 (v/v). These sporophytes grew well in terms of leaf length, number of leaves, and number of roots.