Based on concept and function of garden space,the paper had proposed three elements constituting space which were "ground","roof" and "wall",and pointed out the importance of privacy in public environmental space.Human in gardens had certain requirement for private space,which was contradictory with the open attribute of garden.It was considered that theories on confliction and solution of confliction in TRIZ(Theory of the Solution of Inventive Problems)could help to solve this contradiction.Through analysis on spatial composition forms of modern landscape,based on people's psychological habit,by combining with basic elements of landscape,it had illustrated openness of surface open space,definition of semi-open space and privacy of point enclosed space;discussed possibility to create private landscape in public space;and finally proposed a more reasonable and humanized public space mode of "human-environment-society".