Urban green space (UGS) provides a range of services to visitors and is particularly important for recreation and well-being. There are a number of approaches to research visitor accessibility, but implications for demographic differences of users are typically ignored. In order to more precisely model usage of UGS regarding visitor preference, this study used Guangzhou (China) as a case study, concentrating on residents’ visitation to parks and their factors across different groups (for example, by gender, education level, age and visiting frequency). Online questionnaires from 2360 adults were collected on visiting preferences, such as traveling time, visiting frequency, visit duration within parks, visiting reasons and barriers. Results indicate that women were less likely than men to undertake longer walking trips to access parks (over 40 min). Elderly people tended to have longer visit durations, and lower-educated people tended to have shorter visiting times (particularly less than 15 min) in parks. Visit duration in parks had a positive association with walking time and a negative association with visiting frequency. Furthermore, the proportion of people visiting parks to relieve stress declined with increasing age. Infrequent park users (visiting parks less than once a month) rarely visited to gain inspiration or to socialize with strangers. Barriers to use of parks were correlated with socio-demographic factors, highlighting that older people identified poor quality of parks and long walking times as critical barriers. This study provides evidence that there is no one-size-fits-all modeling approach for UGS usage; instead, it demonstrates the importance of considering the socio-demographic characteristics of users.