This paper, with the Potala Palace Square as the object of study, uses the post occupancy method to carry out a field investigation in a joint manner of questionnaire survey, interviews and behavioral trails observation, so as to analyze the landscape destruction behavior of the Potala Palace Square. The results show that the existing problems in design and management of that square as well as the public are responsible for the destruction; male foreign tourists in all ages, who mostly are the unemployed, students and service employees, prove to be destructors. The Potala Palace Square is characterized by regionalism. Opinions on green effect, management and other options of inland public and local residents vary from one to another. Designers and the administrative department of the square are required to come up with countermeasures to avoid the destruction. In practical design, designers must comply with the thinking of “Design Must be for People” and natural ecological principles, and the administrative department should scientifically manage and maintain the square.