The governance of urban green spaces (UGS) often involves a wide range of stakeholders, each with their own views, preferences, and needs. However, the traditional top-down governance of UGS has struggled to meet the needs of today’s public. By reflecting the different needs of different social groups, public participation has become one of the innovative solutions used to solve the problems of public governance, which has been a widespread concern. Based on the theory of planned behavior (TPB), this study complements environmental responsibility (ER), environmental concern (EC), subjective environmental knowledge (SEK) and media influence (MI) as the factors influencing the formation of citizens' participatory attitude, and provides multiple influencing paths for increasing citizens' participatory intention and behavior. A structural equation model (SEM) was used to test the hypotheses of the newly constructed theoretical model based on 1191 questionnaires administered face-to-face in Beijing. The results demonstrate that perceived behavioral control has the greatest positive influence on citizens’ intentions and behaviors; that is, their intention and behavior to participate is strongly restricted by the objective conditions of the citizens themselves. Among the additional impact factors, expected personal gratification (EPG) also has a positive effect on intention. Local governments can increase citizens’ intentions and behaviors to participate in UGS governance through two measures: one is to optimize the process of citizens’ participation in UGS governance to reduce the threshold of participation; the other is to enhance the city’s infrastructure and cultural and entertainment activities to enhance citizens’ environmental responsibility.