Abstract: To investigate the influence of the natural, perceptual, rest, and activity elements in urban parks on residents’ three mental health dimensions (i.e., positive emotions, cognitive function, and psychological symptoms and negative emotions), and the role of nature connectedness in this context, the current study surveyed 911 Beijing residents and constructed a structural equation model. The results showed that the perceptual elements in urban parks could directly promote residents’ positive emotions and cognitive function, and could also indirectly promote residents’ positive emotions and cognitive function and alleviate psychological symptoms and negative emotions through nature connectedness. In addition, the activity elements in urban parks could directly promote residents’ positive emotions as well as alleviate psychological symptoms and negative emotions. However, the natural and rest elements were not significant predictors for all the dimensions of residents’ mental health. Therefore, emphasis should be placed on increasing the perceptual and activity elements in urban parks, as well as on enhancing human-nature interaction to improve the nature connectedness of residents.