Abstract: Ningbo Moonlake is a lake-dominant public garden with Moonlake as the center, but unlike most lake-public gardens, the Moonlake is a rare one which locates inside the city and develops toward to cultural landmarks of the public gardens in garden history. The lake was established in Tang Dynasty (627—649), thrived in the Song Dynasty and Yuan Dynasty (1086—1094), has been more than 1 400 years. As a public garden which had opened up in Tang Dynasty and existed till now, the Moonlake has experienced four typical stages of the Public Garden formation, has empirical significance and cultural development in ancient city for China public garden. The paper has combined with the complete preservation of the Jiangnan chronicles, untangled construction process of Ningbo Moonlake garden, and put forward a proposal of the mutual influence and common development between garden and city mainly from two aspects of the motivation mechanism of lake public garden evolution which are external form and the internal drive.