It has been widely recognized that urban green space provides various benefits to old adults. However, there is a lack of discussion about the impact of cultural ecosystem services (CES) of green space on seniors’ mental health. We selected 20 parks in the old urban areas of Beijing and collected a total of 693 valid questionnaires from senior residents. Structural equation models were applied to examine the linkage between characteristics of parks (including green space, neighborhood environment, CES) and senior residents’ self-reported ment...