Cyathea is a genus of tree fern, Cyatheaceae is the scaly tree fern family and includes the World’s tallest tree fern which reach heights upto 20m (Large & Braggins, 2004).According to Beniwal (1994) Cyathea gigantea is treated as one of the endangered plants of India. In this study an attempt was made to standardize the in vitro protocol for mass multiplication and conservation of threatened tree fern Cyathea gigantea Wall. ex. Hook, using spore as explants. Spores were found to germinate in Fern Propagation media and MS media. Spores cultured on MS medium showed 72% germination. Sporophytes were induced from the gametophytes on the MS media supplemented with 0.8mg/L IAA and 5mg/L kinetin with highest root length 20.29 cm. Period of germination, Fresh weight of prothallus and length of sporophytes were recorded. In Vitro raised shoots rooted on MS media supplemented with IBA. The well rooted micropropagated plants were transferred to hardening medium for acclimatization where 81% survival percentage was observed.