The present invention refers to a greenhouse (10) for underwater cultivation of terrestrial plant species as well as to an underwater cultivation assembly using it, in which the greenhouse (10) for underwater cultivation of terrestrial plant species is characterised in that it comprises a balloon (11) adapted to being filled with air in an underwater environment (50), the balloon (11) comprising an aperture (12) for lower access, the balloon (11) being made from material that is impermeable to water and permeable to light, the balloon (11) comprising at least one inner support shelf (17) for housing at least one seedbed (53) and means for restraining (14) to the floor (51) of the aquatic basin.
