PURPOSE: Roof greening system and method capable of greening a roof in an inclined structure are provided to enable users to easily install the greening system with the light weight on the roof. CONSTITUTION: A roof greening system comprises the following: first fixing units(110) fixed on a roof with the constant interval； a fresh water unit(120) including a water storing unit, assembled to the first fixing units； a soil supplying unit(130) located on the upper side of the fresh water unit for supplying soil and nutrients； a second fixing unit(140) combining with the first fixing units to fix the soil supplying unit and the fresh water unit in the space between the first and second fixing units； a fresh water unit body located on the upper side of the roof in a box shape with an opening； a partition wall dividing the internal space of the fresh water unit body for storing the water storing unit； and at least one coating layer with waterproof property.본 발명의 일실시예는 지붕 녹화 시스템 및 지붕 녹화 방법에 관한 것으로써, 지붕 녹화 시스템을 경사 형상의 지붕에 원활하게 시공할 수 있고, 녹화에 필요한 물을 충분히 확보할 수 있다.
