From functions, ornament and art, on the basis of the behavioral theory, the utility of urban public facilities was surveyed and studied with Longhua District of Haikou City as an example. It summed up the basis for designing urban public facilities behind behavior habits of residents, in the hope of making future urban construction and management more humanized. Accordingly, it is expected to set up appropriate concept of public facilities, and play especially important role in creating favorable urban living environment.