The quality of public outdoor space has recently become an important issue and has been revealed by many studies. However, there are few studies that show the relationship between the quality of space and the social interaction that occurs between people. The most important goal of urban designers should be to create public open spaces that can meet the various needs of people. Using longer and more frequently, public open spaces allow the fulfilment of needs and also support social interaction. In this context, the concept of 'quality' of public open spaces is gaining importance. The quality of open spaces revealed by different characteristics of the environment has been determined by evaluating of the open spaces by their inclusiveness, meaningful activities, comfort, security and pleasurability and revealed the relationship between social interaction (passive-fleeting-enduring relationship). In order to determine this relationship, a questionnaire was conducted with 140 people (70 people in each park) in Ataturk Square Park and Fatih Park in Trabzon. As a result, a high level of relationship was found between the factors of inclusiveness, comfort and meaningful activities that determine the quality of space and social interaction.