The urban park is the place where dwellers interact with nature, contributing to urban sustainability by providing cultural ecosystem services. To evaluate the cultural ecosystem services of an urban park from the perspective of landsenses ecology, numerous information on visitors' perceptions and experiences is required. With the development of modern information technology as well as dwellers' lifestyles, the social media platform becomes one of the main places for the public to gain information and show opinions. Social media data is characterized by easy to obtain, long span of time, and a large quantity for landsense assessment of an urban park. By extracting and analyzing it, users' specific perceptions and experiences of the given place can be obtained. This study established a framework of landsense assessment of an urban park using social media data and proposing a method for information extraction and indicator design. First, we preprocessed the data, and developed the corpus of senses and park elements, respectively. Then, the texts of positive and negative were divided by sentiment classification to measure users' satisfaction on the relative landsense elements. Based on the above, the perception assessment model was established using the Importance-Performance Analysis (IPA) method. Finally, we conducted a landsense assessment of Yuyuantan Park in Beijing and suggested ways to improve visitors' perception. The conclusions are as follows: vision is a strongly dominant component in people's perception, following touch demission, while perceptions on the hearing dimension are relatively unimportant, and the indicator on smell dimension is still limited. 'Vision of plants', 'vision of humans', 'visual identification', 'vision of water' are the most important landsense elements. Through the perception assessment model, we did not identify the indicator that should be improved urgently, and the indicators that need to be improved secondly include 'vision of humans', 'touch of roads', 'food available', 'feel of wind', 'vision of animals', 'sound of voice', 'sound of plants', and 'vision of roads'.