Urban parks mainly consist of green space and water, which can form park cool islands (PCIs), which substantially alleviate the urban heat island effect. The concept of landsense creation in landsenses ecology can facilitate the rational planning of new urban parks and the optimization of the spatial structure of parks, which help to enhance PCIs and improve the local urban thermal environment. Xiamen, a coastal city in China, was taken as a case study. Landsat-8 Operational Land Imager/Thermal Infrared Sensor imagery data from August 2013 were acquired. A land use type map with a total of 15 urban parks was derived from high-spatial-resolution Google Earth images. Land surface temperature was estimated via an improved single-channel algorithm. Methods including buffer analysis, the landscape pattern index, and multivariate regression were applied to evaluate the key factors of average surface temperature of parks, PCI intensity (i.e., the cooling amplitude), and effective cooling length (L_max). Additionally, based on the concept of landsenses ecology, landsense principles for the creation of urban parks were proposed. The results indicate the following: (1) average temperature (AvT) inside the parks depends on the park size and built-up land area, and both of these factors are non-linearly correlated to AvT (R²=0.915). The threshold value of the park size is approximately 55 hm²; (2) The PCI intensity is mainly determined by the area of green space, the built-up land area inside the park, and the park perimeter-area ratio (PAR). Green space area has a positive impact on PCI intensity, however, the built-up land area and PAR have a negative impact on PCI intensity (R² = 0.911). On the premium of keeping a certain park green space area, it is critical to reduce the built-up area and increase the complexity of the geometric shape of the parks, which is conducive to increasing their PCI intensity and alleviating the urban heat island effect; (3) L_max is mainly determined by park size and the percentage of water area, and both of these factors have a positive impact on L_max (R² = 0.719). On the premium of maintaining a certain park area, it is proposed to enhance the proportion of water bodies in the parks, which helps to increase the L_max value of urban parks; and (4) in the planning and design of urban parks, the concept of landsenses ecology could be employed to consider park size, land use types, the shape index, and the spatial configuration inside the parks to mitigate urban heat island effects.