This study aims to suggest architectural planning elements to improve space use on the public open space as a staying area through a case study. First of all, the survey to count the number of staying users was carried out on 92 public open spaces around Teheran Road in Gangnam District, Seoul. Based on the survey, the case study was carried out by comparing and analyzing characteristics of public open spaces, either when the space is occupied or empty. As a result, it was summarized that the main factors to affect the use of public open space are size, accessibility and legibility, neighbouring facilities, passing circulation through open space and maintenance as resting space with street furniture and landscape. Therefore, it is desirable to maintain space quality by applying different grading factors in the arrangement of incentive on the public open space system.